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I've recently taken on a project with no version control. I don't have any experience with version control myself. I feel it is the only way to go with this project (and probably any future projects now I think of it - I always trust myself too much..)
My question is - where do I begin with implementing version control on a project already in production? Bearing in mind I haven't used version control before so really it's two separate questions:
Starting out with version control
Implementing it on an already live
project
For background, the project is a php/mysql driven website using bits of javascript, I'm working on a (Windows) XAMPP server and I'm very keen to learn this new world of version control!
Congratulations, you are headed in the right direction!
You'll first need to choose a version control system. My current favorite is Git. Unfortunately, I don't think that Git is an easy introduction to version control. I have also used Subversion and Perforce.
Subversion (http://subversion.tigris.org/) works on many platforms, is used in a lot of projects, and has some nice GUI tools available (such as TortoiseSVN on Windows). Command-line tools are also available. It's also free. You can run it in "local filesystem" mode, meaning that you don't need to set up a separate server. It's come a long way from it's "better than CVS" roots.
Perforce (http://www.perforce.com/) is pretty nice. Its Windows implementation seems the best (last I checked, their cross-platform GUI was pretty lousy). You primarily use a GUI to interact with it, though again there are command-line tools. It's commercial software, but open source projects can get free licenses by contacting the company. The biggest drag is that you will need to set up a server. To get started, you could run the server on the same box that you develop on, but that's probably a bad idea in the long run. I found Perforce to be very good for 2-8 person teams; I don't know how well it would work with more.
The big advantage to Git (http://git-scm.com/) is that it requires virtually no set-up. Once installed, you can execute git init in any directory to create a new git repository. The revision history is kept inside the project's directory. You can start out with just local versioning, and you can scale up from there. If Git seems scary, you could also check out Mercurial (https://www.mercurial-scm.org/). I haven't used it, but I understand that it shares some of the same underlying principles as Git.
Avoid CVS. It's on its way out, and no new project should be using it unless they need to do so.
Adding source control to an existing project is easy. The hard part would be making sure that everybody is willing to use source control. If you're working alone, then it's just personal discipline. If you're part of a team, though, and some people have reservations, you will have problems. Try to get everybody on board, and be available to try to answer their questions. If people don't know how to use a tool, they simply won't use it.
Start here: http://svnbook.red-bean.com/
I've found SVN to be the easiest version control system to use, especially for beginners. It's pretty simple to start, the only real decision you have to make is where to host your stuff. There are a couple free svn servers available, but if you're really serious about your work you should host your own.
The first thing to do is to pick a version control paradigm (centralized versus distributed). To answer that, you'll need to take a look at your team and how you intend to handle check-in, check-out, merging, and branching. Once you pick a paradigm, you can choose a version control system. The mainstream systems are Subversion for centralized version control and Git and Mercurial for distributed version control.
If the project is live and working, then that should be your initial check-in to whatever version control you are using. You need a reliable baseline that you can revert to and have 0 work to deploy something that works. If your project is not functional...well, good luck. You might want to check in to start using version control and then decide how you want to proceed (either get the project to a stable and functioning state and then restart your repository or have your initial check-in be a broken system).
If the rest of the team doesn't see the benefit with version control, I would recommend installing your own system on your machine and, at the very least, use it for your own work.
Be prepared for some resistance from management and/or your co-workers. Management may not want to invest the resources for a repository machine -- these things need to be installed, maintained, backed-up, etc. Or they may object to you spending time on an "extra" like a RCS.
Your co-workers, especially if they're unfamiliar with any RCS, are likely to resist using it, or complain that it's too hard to use. There's a learning curve to any new tool, and source control systems are no exception. It's worth the time to learn, though.
My advice is to pick one -- any one that strikes your fancy -- and start using it. Don't worry about getting it 100% perfect the 1st time, it probably won't be any worse than what you have now, which is one misplaced keystroke away from oblivion.
Play with it. Check files out into a separate workspace and hack things up, knowing that it doesn't matter; you can always revert it. Learn how to use your new tool with some GUI frontends (I'm fond of 'svn diff --diff-cmd=kdiff3', myself). Get to the point where you know how to check in & out, tags things, branch, and merge. Then show your co-workers.
Personally, I'm fond of svn, but I didn't choose it; it chose me.
Step 1: Download Mercurial.
Step 2: In your favorite command line, go to the root of your source directory and type hg init.
Step 3: Do a make clean or equivalent (ie. all you want is source, no generated files).
Step 4: Type hg addremove.
Step 5: Type hg commit.
From this point on you can:
Examine the changes between your most recent commit and now: hg diff or hg status.
Make checkpoints in your code: hg commit.
Return to previous checkpoints: hg update -C -r 0
Congratulations, you are now using version control: It's really not that hard, and it's very, very useful (if for no other reason than you can look at the changes you've made to see if they make sense).
At some point you'll probably want to learn about branching (if only so that you have a backup copy of your repository on another machine) at which point you can turn to the documentation or the book.
I don't know if there is something similar for php etc, but an interesting resource here is "Brownfield Application Development in .NET". In many ways, this only uses .NET for the examples; most of the book is really about tackling policies exactly like you mention:
how to introduce source control
how to introduce unit testing
how to introduce continuous integration
etc
and all the concerns/consideration that go with them.
Partly relating to the code; but also relating to the "human" factor; colleagues, managers, etc. I highly recommend it; but you might decide the .NET background is inappropriate for you (it is a good fit for me ;-p).
You can look here: git-for-beginners-the-definitive-practical-guide
This one is a distributed version control system that currently has a good windows support with Git on Windows and a shell extension with TortoiseGit
An addition to other answers:
If the project you want to put under version control have had some releases, and if those versions are available for example as tarfiles (e.g. project-0.1.tar.gz, project-0.2.tar.gz, project-0.3.tar.gz, ...) you might want to consider importing those versions into your chosen version control system. Git for example has import-tars.perl and import-zips.py in contrib/fast-import/ directory, and writing support for other files in other programming languages for git fast-import should be easy.
Sidenote: my preferred version control system is Git.
See also: Good link or book for basics and theory of version control question.
I learned the concepts from the pragmatic series:
example for subversion, they also have books on GIT as well.
I only have experience with SourceSafe and SVN.
SourceSafe seems to have issues with corrupting it's own database, on a team of 5 we were repairing the db probably once a month. It's easy, but still something you shouldn't have to deal with. It's difficult to label code too and use that label for anything practical.
SVN is nice, it's simple to install on Linux or Windows. Most IDEs have a plugin for it, and if you're using Windows there is an Explorer extension (TortoiseSVN) that allows you to do all your operations right from Windows Explorer. There's a lot of SVN tools out there for every OS, it's very well supported. SVN also integrates with TRAC (a bug tracking system), and Bugzilla so you can tie your work tickets to code.
I will say that [HOW you use version control is probably just as, if not more important than which package you use][2]. Using it simply as a library is a very rudimentary application of it, but for a 1-2 man team making a website or an app where you won't be maintaining builds and versions, you'll be ok.
When it comes to version control, anything is better than nothing.
Wow, everyone is just boosting his favorite version control utility.
OK, to answer your question, how do you put a project under version control?
It's not that hard, once you pick a version control utility (be it, git, svn, hg, bzr .. whatever) there's usually a command or two to initialize a repository then add all the relevant files to it.
For instance, in git it might be something like:
$git init
$git add --all
$git commit -m"First commit"
Now, about choosing a version control utility, that's a tough question and highly depends on what you want. You might want to have a look at this question:
Popularity of Git/Mercurial/Bazaar vs. which to recommend
The only tools you should consider choosing among are:
git
svn (Subversion)
hg (Merculiar)
bzr (Bazaar)
mtn (Monotone)
Everything else is either old or commercial.
svn follows a server-client model; there's a central repository. If you're a one-man team then the only thing this means to you is that you have to setup a server and make sure it starts with the computer. Though I heard that you can do away with the server. A bit of googling turns up this guide for using svn without a server
All other tools follow a distributed model, again, if you're a one-man team, the only thing this means to you is that there's no server to setup.
The advantage of svn is that it's been there for a while and has many gui front-ends and better IDE integration.
I can't compare git to hg (merculiar) since I haven't used the latter, but git has a unique storage model compared to svn and hg.
bzr is said to be easier to use, but slower (it's written in python).
I'm personally satisfied with git, but you should do your own research; or maybe just choose one and stick with it. As far as I can tell, they're all mature and stable.
We have 2 kinds of people at my shop:
The ones that starts to check-in the code since the first successful compilation.
The others that only checks-in the code when the project is almost done.
I am part of group 1, and trying to convince people of group 2 to act like me. Their arguments are like the following:
I'm the solo developer of this project.
It's just a prototype, maybe I'll have to rewrite from scratch again.
I don't want to pollute the Source Control with incomplete versions.
If I am right, please help me to raise arguments to convince them. If you agree with them tell me why.
When someone asked for good excuses not to use version control, they got 75 answers and 45 upvotes.
And when they asked Why should my team adopt source control, they got 26 answers.
Maybe you'll find something helpful there.
You don't need "arguments to convince them." Discourse is not a game, and you should not use your work as a debating platform. That's what your spouse is for :) Seriously, though, you need to explain why you care how other devs work on solo projects in which other people are not involved. What are you missing because they don't use source control? Do you need to see their early ideas to understand their later code? If you can sucessfully do that, you may be able to convince them.
I personally use version control at all times, but only because I don't walk a tightrope without a net. Other people have more courage, less time to spend on infrastructure, etc. Note that in 2009, in my opinion, hard disks rarely fail and rewritten code is often better than the code that it replaces.
While I'm answering a question with a question, let me ask another one: does your code need to compile/work/not-break-the-build to be checked in? I like my branches to get good and broken, then fixed, working, debugged, etc. At the same time, I like other devs to use source control however they want. Branches were invented for just that reason: so that people who can't get along do not have to cohabitate.
Here's my view to your points.
1) Even solo developers need somewhere to keep their code when their PC fails. What happens if they accidentally delete a file without source control?
2/3) Prototypes belong in source control so other team members can look at the code. We put our prototype code in a seperate location to the mainline branch. We call it Spike. Here's a great article on why you should keep Spike code- http://odetocode.com/Blogs/scott/archive/2008/11/17/12344.aspx
If I'm the sole developer on a project (in other words, the repository, or part of it, is under my complete control), then I start committing source code as soon as it's written, and I tend to check in after every incremental change, whether or not it works or represents any kind of milestone.
If I'm working in a repository on a project with others, then I tend to try and make my commits such that they don't break the mainline development, pass any tests, etc.
Whether or not it's a prototype, it deserves to go into source control; prototypes represent a lot of work, and lessons learned from them are valuable. Plus, prototypes have an awful habit of becoming production code, which you'll want in source control.
I try to only write code that compiles (everything else is commented out with a TODO/FIXME tag)... and also add everything to source control.
Argument 1: Even as a single dev it's nice to roll back to a running version, to track your progress, etc.
Argument 2: Who cares if it's just a prototype? You might stumble upon a similar problem in six months or so, and then just start looking for this other code...
Argument 3: Why not use more than one repo? I like to file misc stuff to my personal repo.
Start using source control about 20 minutes before you write your first line of your first artifact. There is never a good time to start after you're begun writing things.
some people can only learn from experience.
like a hard drive failure. or coding yourself into a dead-end after deleting code that actually worked
now, i'm not saying that you should erase their hard drive and then taunt them with "if only you had used source control"...but if something like were to happen, hopefully there would be a backup done first ;-)
Early and Often. As the Pragmatic Programmers say, source control is like a time machine, and you never know when you'll want to go back.
I would say to them...
I'm the solo developer of this project.
And when you leave or hand it off we'll have 0 developers. All the more reason to use source control.
The code belongs to the company not you and the company would like some accountability. Checking in code doesn't require too much effort:
svn ci <files> -m " implement ajax support for grid control
Next time someone new wants to make some changes on the grid control or do something related, they will have a great starting point. All projects start off with one or two people. Source control is easier now than it ever was--have they arranged a 30 minute demo of Tortoise SVN with them?
It's just a prototype, maybe I'll have to rewrite from scratch again.
Are they concerned about storage? Storage is cheap. Are they concerned about time wasted on versioning? It takes less time then the cursory email checks. If they are re-writing bits then source control is even more important to be able to reference old bits.
I don't want to pollute the Source Control with incomplete versions.
That's actually a good concern. I used to think the same thing at one point and avoided checking in code until it was nice and clean which is not a bad thing in and of itself but many times I just wanted to goof around. At this point learning about branching helps. Though I wish wish SVN had full support for purging folders like Perforce.
Let see their arguments:
I'm the solo developer of this project.
It's just a prototype, maybe I'll have to rewrite from scratch again.
I don't want to pollute the Source Control with incomplete versions.
First, the 3rd one. I can see the reasoning, but it is based on a bad assumption.
At work, we use Perforce, a centralized VCS, and indeed we only check in source that compile successfully and doesn't break anything (in theory, of course!), after peer review.
So when I start a non trivial change, I feel the need to intermediary commits. For example, recently I started to make some changes (somehow, in solo for this particular task, so I address point 1) on a Java code using JDom (XML parsing). Then I was stuck and wanted to use Java 1.6's built in XML parsing. It was obviously time to keep a trace of the current work, in case my attempt was failed and wanted to go back. Note this case somehow addresses the point 2.
The solution I chose is simple: I use an alternative SCM! Although some centralized VCS like SVN are usable in local (on the developer's computer), I was seduced by distributed VCS and after briefly testing Mercurial (which is good), I found Bazaar better suited to my needs and taste.
DVCS are well suited for this task because they are lightweight, flexible, allow alternative branches, doesn't "pollute" the source directory (all data is in one directory at the root of the project), etc.
By making a parallel source management, you don't pollute the source of other developers, while keeping the possibility to go back or quickly try alternative solutions.
At the end, by committing the final version to the official SCM, the result is the same, but with added security at the level of the developer.
I'd like to add two things. With version control you can:
Revert to last version that worked, or at least check how it looked like. For that you would need SCM which supports changesets / uses whole-tree commits.
Use it to find bugs, by using so called 'diff debugging' by finding commit in history that introduced the bug. You would want SCM which support it in automated or semi-automated fashion.
Personally, I often start version control after the first sucessful compile.
I just wonder why nobody mentioned distributed version control systems in this context: If you could manage to switch over to a distributed system (git, bazaar, mercury), most arguments of your second group would become pointless since they can just start their repository locally and push it to the server when they want (and they can also just remove it, if they want to restart from scratch).
For me, it's about having a consistent process. If you are writing code, it should follow the same source control process that your production code does. That helps build and enforce good development practices across the development team.
Categorizing the code as a prototype or other non-production type of project should just be used to determine where in the source control tree you put it.
We use both CVS (for non .NET projects) and TFS (for .NET projects) where I work, and the TFS repository has a Developer Sandbox folder where developers can check in personal experimental projects (prototypes).
If and when a project starts to get used in production, the code is moved out of the Developer Sandbox folder into it's own folder in the main tree.
I would say you should start adding the source and checking in before you even build the first time. It is then much easier to avoid checking in generated artifacts. I always use some source control, even for my small hobby hacks, just because it automatically filters the relevant from the noise.
So when I start prototyping I might create a project and then before building it I do "git init, git add ., git commit -a -m ..." just so that when I want to move the interesting parts I just clone over using git and then I can add it to the subversion repository or whatever is used where I am working at the moment.
It's called branching people try to get with the program :p Prototyping? Work in a branch. Experimenting? Work in a branch. New feature? Work in a branch.
Merge your branches into the main trunk when it makes sense.
I guess people tend to be laid back when it comes to setting up source control initially if the code may never be used. I have projects I coded belonging to both groups and the ones outside source control are not less important. It is one of those things that gets postponed everyday when it really should not.
On the other hand I sometimes commit too seldom complicating a revert once I screw up some CSS code and not knowing what I changed e.g. to make the footer of the site end up behind the header.
I check-in the project in source control before I start coding.
The first thing I do is create and organize the projects and support files (such as .sln files in .NET development) with the necessary support libraries and tools (usually in a lib folder) I know I will use in my project.
If I already have some code written, then I add it too, even if it is an incomplete application. Then I check-in everything. From there, everything is as usual, write some code, compile it, test it, check-in it...
You probably won't need to branch from this point or revert your changes, but I think it is a good practice to have everything under source control since the beginning, even if you don't have anything to compile.
I create a directory in source control before I start writing code for a project. I do the first commit after creating the project skeleton.
i'm drunk and and i do first git -init and then vim foo.cpp.
Any decent modern source control platform (of which VSS is not one) should not in any way be polluted by putting source code files into it. I am of the opinion that anything that has a life expectancy of more than about 1/2 an hour should be in source control as early as possible. Solo develpment is no longer a valid excuse for not using source control. It is not about security it is about bugs and long term history.
I want to set up a source code control system that:
is networked, so users can access it at work or on the road
does not need to provide sharing, lock mode is sufficient
there will be only three users and they will never be working with the same code
we have no system administrator and not much knowledge in that area so the set up and config must be dead simple.
will be installed on a Windows server
open source or free
Suggestions please.
the SIMPLEST system is what we here call the "Hey Chris" system. We have a networked drive that everyone can mount, and if you want to edit something you shoud "Hey, Chris, are you working on blahblah.cpp?" and Chris says "Nope." and then you edit blahblah.cpp, and stick it back on the shared drive... If you want versions, just back up the networked drive every night.
I never said it was the BEST system, just the simplest.
SVN covers all of these, and is quite easy to set up.
Wrt point 2, sharing tends to be better than locking, as a file that is locked by someone who then goes on holiday/dies/etc. needs to be unlocked by someone before it can be worked on by another developer. SVN supports sharing 'out of the box'.
Mercurial or Git
Try Subversion (svn).
Edit: Rich beat me to it =D. And yes, as he points out sharing is better than locking. Sounds like you're a SourceSafe user. Those were the same set of problems I was trying to address when moving out from SourceSafe =)
I'm surprised no one recommended the Fossil version control system. It checks all of the askers requirements. It's stable and simple, consists of just a single self-contained executable, allows easy admin with a UI and only uses HTTP(s). And yeah, runs on Windows.
In addition it provides a nice web interface, and also manages bug tracking, and wikis.
It's made (and used) by the SQLite people, and that's a guarantee of reliability for me.
The simplest version control system I am aware of is a Revision Control System RCS. It is a command line utility that is available out of the box on Linux systems. It's usage is quite simple.
First. Inside current directory, create a directory where RCS's information will be stored:
$ mkdir RCS
Second. Store (check-in) a file into RCS:
$ ci -t-"My notes" notes.txt
Original file gets deleted.
Third. Restore (check-out) original file from RCS:
$ co -u notes.txt
Fourth. Edit file as needed, now it can be restored any time:
$ vim notes.txt
RCS is also working with binary files, and supports many subsequent changes to a file.
I can only add my voice to the "use subversion" chorus. But you were also asking about simple installation and administration.
For that I would point you to VisualSVN Server. It is an easy to use server installation on Windows. And it is free.
Or if you want to go with a manual setup (maybe because you don't want to use the apache bundled with visualsvn server) follow Jeff's Setting up Subversion on Windows.
I really dig Git and GitHub for this. Git is nice because each developer can check things in and go through the history even when they're offline (say, on an airplane or in the backwoods somewhere), then push their changes to a central repository when they are back online. GitHub works really, really well as that central repository, and includes a lot of very handy tools for reviewing and commenting on other people's checkins.
The basic commands that you use day-by-day boil down to:
git add .
git commit -m "this is a note"
git pull origin master
git push
Git handles most conflicts very well, and it's fast, fast, fast, since the entire repository is on each machine.
Kyle Cordes wrote a blog post about getting started on Windows.
I recommend Tortoise SVN. SVN is a source control environment that's easy to set up and use on Windows, and Tortoise is an add on that integrates with windows explorer.
Despite being simple to use, it allows different people to work on the same file and merge their changes. Even though that "can't happen" I predict at some point you'll be happy that it works that way.
Darcs provides all this and a lot more. It's a distributed version contoll system, which would make it easier to access the data on the road. You can send/receive patches (similar to revisions) through email or ssh.
The thing about darcs that I like the most is that it's really verbose. It really tries to help you.
Lots of recommendations for SVN, but I'm not sure I'd call that "simplest" from an admin point of view. You still need to set up a server, IIRC. In comparison, a DVCS like Mercurial makes no distinction between "repository" and "working copy". To put something on a server (which can be any folder you have file-sharing access to), you can just "push" it there.
You also mention working on the road. DVCS are particularly good at this. Your laptop will have the whole history, so you only need to touch the server if you want to push or pull, not just to do a diff or check the history.
I've never really worked with a lot of people where we had to check out code and have repositories of old code, etc. I'm not sure I even know what these terms mean. If I want to to start a new project that involves more than myself that tracks all the code changes, does "check out" (again, don't know what that means), how do I get started? Is that what SVN is for? Something else? Do I download a program that keeps up with the code?
What do I do?
It will all be in house. No Internet for storing code.
I don't even know if what I am asking for is called source control. I see things about checking out, SVN, source control, and so on. I don't know if it is all talking about the same thing or not. I was hoping to use something open source.
So, a long time ago, in the bad old days of yore, source control used a library metaphor. If you wanted to edit a file, the only way to avoid conflicts was to make sure that you were the ONLY one editing the file. What you'd do is ask the source control system to "check out" that file, indicating that you were editing it and nobody else was allowed to edit it until you made your changes and the file was "checked in". If you needed to make a change to a checked out file, you had to go find that freakin' developer who'd had everythingImportant.conf checked out since last Tuesday..freakin' Bill...
Anyway, source control doesn't really work like that anymore, but the language stuck with us. Nowadays, "checking out" code means downloading a copy of the code from the code repository. The files will appear in a local directory, allowing you to use them, compile the code, and even make changes to the source that you could perhaps upload back to the repository later, should you need to. Even better, with just a single command, you can get all the changes that have been made by other developers since the last time you downloaded the code. Good stuff.
There are several major source control libraries, of which SVN (also called Subversion) is one (CVS, Git, HG, Perforce, ClearCase, etc are others). I recommend starting with SVN, Git, or HG, since they're all free and all have excellent documentation.
You might want to start using source control even if you're the only developer. There's nothing worse than realizing that last night the thousand lines of code you deleted as useless were actually critically important and are now lost forever. Source control allows you to zoom forwards and backwards in the history of your files, letting you easily recover stuff that you should not have removed, and giving you a lot more confidence about deleting useless stuff. Plus, fiddling around with it on your own is good practice.
Being comfortable with source/revision control software is a critical job skill of any serious software engineer. Mastering it will effectively level you up as a professional developer. Coming onto a project and finding that the team keeps all their source in a folder somewhere is an awful experience. Good luck! You're already on the right path just by being interested!
Check out Eric Sink's excellent series of articles:
Source Control HOWTO
I recommend Git and Subversion (SVN) both as free, open-source version control systems that work very well. Git has some nice features given that it can be easier to work decentralized.
Checkout means retrieving a file from a source control system. A source control system is a database (some, like CVS, use just specially marked up text files, but a file system is also a database) that holds all versions of your code (that are checked in after you make modifications).
Microsoft Visual SourceSafe uses a very proprietary database which is prone to corruption if it is not regularly maintained and uses reserved checkouts exclusively. Don't use it, for all those reasons.
The difference between a reserved checkout and an unreserved checkout is in an unreserved checkout; two people can be modifying the same file at once. The first one to check in gets in no problem, and the second one has to update their code to the latest version and merge the changes into theirs (which usually happens automatically, but if the same area of the file was changed, then there is a conflict, which has to be resolved before it can be checked in).
For some arguments for unreserved checkouts, see here.
Following this, you will be looking at a build process that independently checks out the code and builds the source code, so that everyone's changes are built and distributed together.
Are you creating the project that requires source control? If so, choose a source control system that meets your needs, and read the documentation for how to get it set up. If you are simply using a previously set up source control system for an existing project, ask a coworker who has been using it, or ask the person who set up the source control system.
For choosing a source control system that meets your needs, most source control systems have extensive descriptions of their features online, many provide evaluation or even completely free products, and there are many many many anecdotal descriptions of what working with each individual source control system is like, which can help.
Just don't use Microsoft Visual SourceSafe if you value your sanity and your code.
After being told by at least 10 people on SO that version control was a good thing even if it's just me I now have a followup question.
What is the difference between all the different types of version control and is there a guide that anybody knows of for version control that's very simple and easy to understand?
We seem to be in the golden age of version control, with a ton of choices, all of which have their pros and cons.
Here are the ones I see most used:
svn - currently the most popular open source?
git - very hot since Linus switched to it
mercurial - some smart people I know swear by it
cvs - the one everybody is switching from
perforce - imho, the best features, but it's not open source. The two-user license is free, though.
visual sourcesafe - I'm not much in the Microsoft world, so I have no idea about this one, other than people like to rag on it as they rag on everything from Microsoft.
sccs - for historical interest we mention this, the great-grandaddy of many of the above
rcs - and the grandaddy of many of the above
My recommendation: you're safest with either git, svn or perforce, since a lot of people use them, they are cross platform, have good guis, you can buy books about them, etc.
Dont consider cvs, sccs, rcs, they are antique.
The nice thing is that, since your projects will be relatively small, you will be able to move your code to a new system once you're more experienced and decide you want to work with another system.
Eric Sink has a good overview of source control. There are also some existing questions here on SO.
To everyone just starting using version control:
Please do not use git (or hg or bzr) because of the hype
Use git (or hg or bzr) because they are better tools for managing source code than SVN.
I used SVN for a few years at work, and switched over to git 6 months ago. Without learning SVN first I would be totaly lost when it comes to using a DVCS.
For people just starting out with version control:
Start by downloading SVN
Learn why you need version control
Learn how to commit, checkout, branch
Learn why merging in SVN is such a pain
Then switch over to a DVCS and learn:
How to clone/branch/commit
How easy it is to merge your branches back (go branch crazy!)
How easy it is to rewrite commit history and keep your branchesup to date with the main line (git rebase -i, )
How to publish your changes so others can benefit
tldr; crowd:
Start with SVN and learn the basics, then graduate to a DVCS.
I would start with:
A Visual Guide to Version Control
Wikipedia
Then once you have read up on it, download and install SVN, TortoiseSVN and skim the first few chapters of the book and get started.
Version Control is essential to development, even if you're working by yourself because it protects you from yourself. If you make a mistake, it's a simple matter to rollback to a previous version of your code that you know works. This also frees you to explore and experiment with your code because you're free of having to worry about whether what you're doing is reversible or not. There are two major branches of Version Control Systems (VCS), Centralized and Distributed.
Centralized VCS are based on using a central server, where everyone "checks out" a project, works on it, and "commits" their changes back to the server for anybody else to use. The major Centralized VCS are CVS and SVN. Both have been heavily criticized because "merging" "branches" is extremely painful with them. [TODO: write explanation on what branches are and why merging is hard with CVS & SVN]
Distributed VCS let everyone have their own server, where you can "pull" changes from other people and "push" changes to a server. The most common Distributed VCS are Git and Mercurial. [TODO: write more on Distributed VCS]
If you're working on a project I heavily recommend using a distributed VCS. I recommend Git because it's blazingly fast, but is has been criticized as being too hard to use. If you don't mind using a commercial product BitKeeper is supposedly easy to use.
The answer to another question also applies here, most importantly
Jon Works said:
The most important thing about version control is:
JUST START USING IT
His answer goes into more detail, and I don't want to be accused of plaigerism so take a look.
The simple answer is, do you like Undo buttons? The answer is of course yes, because we as human being make mistakes all the time.
As programmers, its often the case though that it can take several hours of testing, code changes, overwrites, deletions, file moves and renames before we work out the method we are trying to use to fix a problem is entirely the wrong one and the code is more broken than when we started.
As such, Source Control is a massive Undo button to revert the code to an earlier time when the grass was green and the food plentiful. And not only that, because of how source control works, you can still keep a copy of your broken code, in case a few weeks down the line you want to refer to it again and cherry pick any good ideas that did come out of it.
I personally (though it could be called overkill) use a free Single user license version of Source Gear Fortress (which is their Vault source control product with bug tracking features). I find the UI really simple to use, it supports both the checkout > edit > checkin model and the edit > merge > commit model. It can be a little tricky to set up though, requiring you to run a local copy of ISS and SQL server. You might want to try a smaller program, like those recommended by other answers here. See what you like and what you can afford.
Mark said:
git - very hot since Linus switched to it
I just want to point out that Linus didn't switch to it, Linus wrote it.
If you are working by yourself in a Windows environment, then the single user license for SourceGear's Vault is free.
We use and like Mercurial. It follows a distributed model - it eliminates some of the sense of having to "check in" work. Mozilla has moved to Mercurial, which is a good sign that it's not going to go away any time soon. One con, in my opinion, is that there isn't a very good GUI for it. If you're comfortable with the command line, though, it's pretty handy.
Mercurial Documentation
Unofficial Manual
Just start using source control, no matter what type you use. What you use doesn't matter; it's the use of it that is important
Like everyone else, SC is really dependant on your needs, your budget, your environment, etc.
At its root, source control is designed to provide a central repository of all your code, and track who did what to it when. There should be a complete history, and you can get products that do full changelogs, auditing, access control, and on and on...
Each product that is out there starts to shine (so to speak) when you start to look at how you want or need to incorporate SC into your environment (whether it's your personal code and documents or a large corporations). And as people use them, they discover that the tool has limitations, so people write new ones. SVN was born out of limitations that the creators saw with CVS. Linus wanted something better for the Linux kernel, so now we have git.
I would say start using one (something like SVN which is very popular and pretty easy to use) and see how it goes. As time progresses you may find that you need some other functionality, or need to interface with other systems, so you may need SourceSafe or another tool.
Source control is always important, and while you can get away with manually re-numbering versions of PSD files or something as you work on them, you're going to forget to run that batch script once or twice, or likely forget which number went with which change. That's where most of these SC tools can help (as long as you check-in/check-out).
See also this SO question:
Difference between GIT and CVS