This is a comparison of version-control systems. It is split into several categories and sub-categories under which the systems are checked.
Support for atomic commits means that if an operation on the repository is interrupted in the middle, the repository will not be left in an inconsistant state. Are the check-in operations atomic? Are the check-in operations atomic, or can interrupting an operation leave the repository in an intermediate state?
| CVS | No. CVS commits are not atomic. |
| Aegis | Commits are atomic. |
| Arch | Yes. Commits are atomic. |
| BitKeeper | Yes (but need to verify) |
| CMSynergy | Yes. Commits are atomic. |
| Co-Op | Yes. Commits are atomic. |
| Darcs | Yes. Commits are atomic. |
| Monotone | Yes. |
| OpenCM | Yes. Commits are atomic. |
| Perforce | Yes. Commits are atomic. |
| Subversion | Commits are atomic. |
| svk | Commits are atomic. |
| Vesta | Yes. Commits are atomic. |
| Visual SourceSafe | No. VSS commits are not atomic. |
Does the system support moving a file or directory to a different location while still retaining the history of the file?
| CVS | No. Renames are not supported and a manual one may break history in two. |
| Aegis | Yes. Renames are supported. |
| Arch | Yes. Renames are supported. |
| BitKeeper | Yes. Renames are supported. |
| CMSynergy | Yes. Renames are supported. |
| Co-Op | Renames of files are supported. Renaming a directory requires creating a new one, moving the files and deleting the old one. Moved file histories are preserved. |
| Darcs | Yes. Renames are supported. |
| Monotone | Yes. Renames are supported. |
| OpenCM | Yes. Renames are supported |
| Perforce | Not directly (you copy and then delete but it manages to keep track of the branch; the item below allows for this very feature) |
| Subversion | Yes. Renames are supported. |
| svk | Yes. Renames are supported. |
| Vesta | Yes. The unit of checkout/checkin is a directory tree. Files and directories can be added, deleted, and renamed between versions. |
| Visual SourceSafe | Affects the whole history, it's like renaming a file in the CVS repository. There is a kludgy workaround using "share-rename,move,delete" that gets what you want. |
Does the version control system supports copying files or directories to a different location at the repository level, while retaining the history?
| CVS | No. Copies are not supported. |
| Aegis | No. Copies are not supported. |
| Arch | No. Copies of files and directory structures are not supported. |
| BitKeeper | Yes. Copies are supported. |
| CMSynergy | Yes, and it's a very cheap operation (update the target directory to include the new file/directory). |
| Co-Op | Copying doesn't retain history, moving does. |
| Darcs | No. Copies of files and directory structures are not supported. |
| Monotone | Yes. Copies are supported |
| OpenCM | No. Copies are not supported. |
| Perforce | Copies are supported (though, because of its architecture, I don't know how well) |
| Subversion | Yes. And it's a very cheap operation (O(1)) that is also utilized for branching |
| svk | Yes. Same as subversion. |
| Vesta | Yes. A new package/branch can be based on any existing version without affecting the past history. (This is also an O(1) operation.) |
| Visual SourceSafe | Yes. Copies are supported up to a point. |
Does the system support cloning a remote repository to get a functionally equivalent copy in the local system? That should be done without any special access to the remote server except for normal repository access.
| CVS | No. |
| Aegis | Yes. |
| Arch | Yes. |
| BitKeeper | Yes. |
| CMSynergy | Yes, as long as you have the (more expensive) Distributed package. |
| Co-Op | Repositories are always replicated on local machines. There is no central server. |
| Darcs | Yes. |
| Monotone | Yes. |
| OpenCM | No. |
| Perforce | Yes. Via the Perforce Proxy (P4P) tool. |
| Subversion | Indirectly, by using Chia-Ling Kao's SVN::Mirror add-on or Shlomi Fish' svn-push utility. |
| svk | Yes. |
| Vesta | Yes. Replication is a fundamental part of the design. |
| Visual SourceSafe | Not directly possible with the included GUI or command line tools; ssarc and ssrestor might be useable |
Can the system propagate changes from one repository to another?
| CVS | No. |
| Aegis | Yes. |
| Arch | Yes. |
| BitKeeper | Yes. |
| CMSynergy | Yes, as long as you have the (more expensive) Distributed package. |
| Co-Op | It's a peer-to-peer system, which keeps all replicas of the repository in sync. |
| Darcs | Yes. |
| Monotone | Yes. |
| OpenCM | No. |
| Perforce | Unknown. Probably Not. |
| Subversion | Yes, using either Chia-Ling Kao's SVN::Mirror script or the svn-push utility by Shlomi Fish. |
| svk | Yes. |
| Vesta | Yes. |
| Visual SourceSafe | Not directly possible with the included GUI or command line tools; ssarc and ssrestor might be useable |
Is it possible to define permissions on access to different parts of a remote repository? Or is access open for all?
| CVS | Limited. "pre-commit hook scripts" can be used to implement various permissions systems. |
| Aegis | Yes. Aegis relies on the UNIX permissions system to implement permissions for files in the repository. |
| Arch | Yes. It is possible to define permissions on access to different parts of a remote repository based on the permission systems of the underlying protocol. |
| BitKeeper | FILL IN |
| CMSynergy | No, though a single server can serve many repositories. |
| Co-Op | First access (joining the project) requires administrator's approval. Subsequent access to that project is not controlled. |
| Darcs | No. |
| Monotone | Yes. It is possible to restrict incoming changes from certain sources to be performed only in certain parts of the repository. |
| OpenCM | Permissions are defined on a per-branch basis. |
| Perforce | Yes. (more than half a dozen of permission levels that can be set in a file by file basis) |
| Subversion | Yes. The WebDAV-based service supports defining HTTP permissions for various directories of the repository. |
| svk | Same as subversion. |
| Vesta | Yes. Access permissions for each package (the unit of checkout/checkin) can be different. Access permissions for a branch can be different from the basis package. |
| Visual SourceSafe | Project specific permissions (read, write, delete, destroy) can be set per user; but see "Networking Support": this makes "Repository Permissions" a hindrance to accidental damage but cannot prevent intentional damage. |
Does the repository supports changesets? Changesets are a way to group a number of modifications that are relevant to each other in one atomic package, that can be cancelled or propagated as needed.
| CVS | No. Changes are file-specific. |
| Aegis | Yes. Changesets are supported. |
| Arch | Yes. Changesets are supported. |
| BitKeeper | Yes. Changesets are supported. |
| CMSynergy | Yes. Changesets (or tasks) are fundamental to the way Synergy works. |
| Co-Op | Yes. Changesets are the default. |
| Darcs | Yes. Changesets are supported. |
| Monotone | Yes. Changesets are supported. |
| OpenCM | Yes. Changesets are supported. |
| Perforce | Yes. Changesets are supported. |
| Subversion | Partial support. There are implicit changeset that are generated on each commit. |
| svk | Same as subversion. |
| Vesta | Not exactly. Vesta uses a related concept of configurations instead, which some has similar properties. |
| Visual SourceSafe | No. Changes are file-specific. |
Does the version control system has an option to track the history of the file line-by-line? I.e: for each line show at which revision it was most recently changed, and by whom?
| CVS | Yes. cvs annotate |
| Aegis | Yes. aeannotate |
| Arch | Not in the command line client, but ViewARCH, a web-interface for Arch, has it. |
| BitKeeper | Yes. (bk annotate) |
| CMSynergy | Probably, if you're a sufficiently proficient hacker with their scripting language. |
| Co-Op | Not directly, but it's possible to compare any two versions using a visual differ. |
| Darcs | Yes. (darcs annotate) |
| Monotone | No. |
| OpenCM | Unknown. Probably not. |
| Perforce | Yes, an annotation feature is present. |
| Subversion | Yes. (svn blame) |
| svk | Yes. (svk blame) |
| Vesta | No, but it would be easy to implement a tool that did this, as the Vesta repository provides direct filesystem access to all versions. |
| Visual SourceSafe | Not directly, but it's possible to compare any two versions using a visual differ. |
Can the version control system checkout only one directory of the repository? Or restrict the check-ins to only one directory?
| CVS | Yes. |
| Aegis | No. All changes are made repository-wide. |
| Arch | It is possible to commit only a certain directory. However, one must check out the entire repository as a whole. |
| BitKeeper | No. All changes are made repository-wide. |
| CMSynergy | Yes and no. Files and directories are checked out and in individually, however you have to work in the context of a project, which consists of one or more directories. |
| Co-Op | No. All changes are made to a project as a unit, but it's possible to access each file's history separately. |
| Darcs | It is possible to commit only a certain directory. However, one must check out the entire repository as a whole. |
| Monotone | No. All changes are tree-wide. |
| OpenCM | No. All changes are made to a project as a unit |
| Perforce | Yes. Changes to a sub-directory of the repository are supported. |
| Subversion | Yes. |
| svk | Yes. |
| Vesta | Yes and no. The unit of checkout/checkin (called a package) is a directory tree. Most projects use more than one. Once created, a package must be checked out/in as a unit. |
| Visual SourceSafe | Yes. |
Does the software has an ability to track the changes in the working copy that were not yet commited to the repository?
| CVS | Yes. Using cvs diff |
| Aegis | Yes. Using aediff. |
| Arch | Yes, using "tla changes". |
| BitKeeper | Yes. Using bk diff. |
| CMSynergy | Yes, either using integrated diff tool or user-configured external diff tool |
| Co-Op | Yes, using built-in visual differ/editor. |
| Darcs | Yes, using "darcs whatsnew". |
| Monotone | Yes. In a similar fashion to CVS. |
| OpenCM | Yes. Using cm diff |
| Perforce | Yes. |
| Subversion | Yes. Using svn diff |
| svk | Yes. Using svk diff |
| Vesta | Yes. Intermediate immutable snapshots can be taken during an active checkout (with vadvance). These intermediate versions can be treated just like checked in versions: they can be replicated to other repositories and used as the basis for branches. |
| Visual SourceSafe | Yes, using integrated diff tool. |
Does the system has a way to assign a per-file commit message to the changeset, as well as a per-changeset message?
| CVS | No. Commit messages are per change. |
| Arch | No. |
| BitKeeper | Yes. It is possible to have a per-file commit message |
| CMSynergy | Yes. |
| Co-Op | No. Commit messages are per change. They go to all project members and update their repositories. |
| Darcs | No. |
| Monotone | Yes. It is possible to attach a comment to a certain file at a certain revision. |
| OpenCM | Unknown. |
| Perforce | No. Commit messages are per change. |
| Subversion | No. There is no such feature. |
| svk | No. There is no such feature. |
| Vesta | Not exactly. The unit of checkin is a directory, and commit messages are assigned at that level, not to individual files. Since configurations are also versioned, they also have commit messages. |
| Visual SourceSafe | Since changesets are not supported, yes. |
How well is the system documented? How easy it is to get started using it?
| CVS | Excellent. There are many online tutorials and resources and an online book. The command line client also provides an online comprehensive help system. |
| Aegis | Medium. The documentation is given in several large scope troff documents, that are only usable as not-so-PDFish PDF documents, and as text documents that lack any formatting. It is very hard to get started using it with the online resources. The content is of good quality, but otherwise not made very accessible. |
| Arch | Medium. There are two online tutorials and a comprehensive online documentation. The command line client also supplies a reference page. However, some of the documentation is out of date or incomplete. |
| BitKeeper | Very good. There is a comprehensive help at the BitKeeper site. Each command is documented in its own man page, and the client contains a help tool that offers an integrated help system. |
| CMSynergy | Medium. Lots of books, plus somewhat clunky set of HTML pages, but has some radical concepts which can cause real problems really quickly. They recommend a day's training for basic users, more for more advanced users. Took a while to become fluent. |
| Co-Op | Very good. Step-by-step tutorial and HTML help is included. |
| Darcs | Good. The manual contains a brief tutorial and a solid reference. Every sub-command can print its usage. Because the command-set is small and the model is simple, many users find it easy to get started. |
| Monotone | Good. There's an overview and tutorial written in Texi, and a man page. The client supplies documentation for every command. |
| OpenCM | Well documented. |
| Perforce | Very Good (html and command line help) |
| Subversion | Very good. There is a free online book and some online tutorials and resources. The book is written in DocBook/XML and so is convertible to many different formats. The command-line client also provides a good online help system that can be used as a reference. |
| svk | Very poor at this moment. |
| Vesta | Quite thoroughly (HTML, man pages, published papers, a book-length research report). |
| Visual SourceSafe | Medium. Help file which is sometimes useful. However, the interface is reasonably intuitive so documentation isn't needed as much. |
How easy it is to deploy the software? What are the depenedencies and how can they be satisfied?
| CVS | Good. Out of being the de-facto standard, CVS is available on most systems and is easy to deploy. |
| Aegis | The Aegis binary should be installed as SUID-root, and so requires root privileges to install. It also not very portable to Win32 systems. Other than that, Aegis supports an easy autoconf or RPM/apt-based installation process. |
| Arch | Excellent. An arch service is nothing but a filesystem-space hosted by any of its supported protocols (FTP, SFTP, WebDAV, etc.). The arch client is written in C, and is portable across UNIX systems (and on Win32 only with a UNIX emulation layer). |
| BitKeeper | Good. All that is required is downloading a binary for the system and installing it using the installation script. The package is self-contained and is easy to set up. |
| CMSynergy | Medium. There is a detailed install guide for setting it up using a binary kit and a set of scripts. However it still took several tries to get it properly installed and configured. The Windows client is a slightly clunky Windows installer. |
| Co-Op | Very easy to deploy, since there is no central server. Can be configured to use e-mail or LAN (or both) for synchronization. For e-mail, requires MAPI-compliant e-mail client. |
| Darcs | Very good. darcs requires few external libraries, however you need the Glasgow Haskell Compiler if you cannot find a binary. To start working, just "darcs init". |
| Monotone | Excellent. It is possible to copy or compile the executable to the user's machine, without any configuration or external dependencies. |
| OpenCM | Very good. Install the RPM, or build from tarball and install the init script. |
| Perforce | Very good. Perforce is very easy to deploy. |
| Subversion | A Subversion service requires installing Berkeley DB 4.0, as well as either a dedicated Apache module, or its own proprietary server. The client requires only the Subversion-specific logic and the Neon WebDAV library. Installation of the components is quite straightforward, but will require some work. |
| svk | In addition to installing subversion, users are required to install the subversion perl bindings and a few modules from CPAN. |
| Vesta | Medium to Good. There is a detailed installation guide for setting it up using a binary kit. RPMs and Debian packages have been recently released. There are no dependencies on other software. Vesta, however, is required to build itself. |
| Visual SourceSafe | Very good - an installation package which does the work. When you create a repository it installs the exe's in a directory and you can run them from there if you need to. |
What is the command set? How compatible it is with the commands of CVS (the current open-source defacto standard)?
| CVS | A simple command set that includes three most commonly used commands (cvs commit, cvs update and cvs checkout) and several others. |
| Aegis | A complex command set that involves many operations just to get started. Not CVS-compatible. (albeit support for such basic operations was contemplated) Note that Aegis is a Software Configuration Management system and not just a simple version control system, which may justify this extra complexity. |
| Arch | Many commands are compatible with CVS or BitKeeper. However, there are many other commands for it for different uses. Aliasing of commands is possible so it it may be possible to make it more compatible. |
| BitKeeper | A CVS-like command set with some easy-to-get-used-to complications due to its different way of work and philosophy. |
| CMSynergy | An extensive and powerful command set, which has some CVS similarity, though the architecture is so different that it quickly moves away for anything but the basics. |
| Co-Op | Basic commands are compatible with CVS. |
| Darcs | The command set is fairly compact and the core commands are easy to understand. Follows CVS in a few places, but since the model is different most commands are unique. |
| Monotone | Tries to follow CVS conventions, but deviates where there is a different design. |
| OpenCM | A CVS-like command set that is familiar to existing CVS users. |
| Perforce | Very extensive but not compatible with CVS. |
| Subversion | A CVS-like command set which is easy to get used to for CVS-users. |
| svk | A CVS-like command set which is easy to get used to for CVS-users. |
| Vesta | The command set is unrelated to CVS. Most of the time, users use about 5 commands. Few ever need to know more than about 20 commands. |
| Visual SourceSafe | A bit of an afterthought. It's possible to do basic things, but it's really geared up for using the GUI. |
How well is the networking integration in the system? How compliant it with existing protocols and infra-structure.
| CVS | Good. CVS uses a proprietary protocol with various variations for its client/server protocol. This protocol can be tunneled over an SSH-connection to support encryption. |
| Aegis | Poor. Aegis is filesystem-oriented and so can be networked only via NFS (network file-system) or a similar protocol. There exists some HTTP-functionality, but it is quite limited. |
| Arch | Excellent. Arch can utilize a multitude of protocols for its service, which is nothing but a dumb remote filesystem server. Currently supported protocols include FTP, SFTP, WebDAV (remote file access over HTTP), as well as any remote filesystem protocol (NFS, SMB). |
| BitKeeper | Good. Repositories can be checked out from remote over HTTP, and BitKeeper also sports its own proprietary protocol for communicating between one repository and the other. |
| CMSynergy | Good (single TCP/IP socket) |
| Co-Op | Uses the simplest LAN interface: copying files between shared directories. |
| Darcs | Good. Darcs supports getting patches over HTTP, and getting and sending patches over SSH and email. |
| Monotone | Good. Uses a custom protocol called "netsync". |
| OpenCM | Good. Uses its own proprietary client/server protocol. |
| Perforce | Good. (single TCP/IP socket) |
| Subversion | Very good. The Subversion service can use either WebDAV+DeltaV (which is HTTP or HTTPS based) as its underylying protocol, or its own proprietary protocol that can be channeled over an SSH connection. |
| svk | Very good. svk uses SVN::Mirror to retrieve remote repository. There has been plans to add VCP support to SVN::Mirror so it will be able to mirror from arbitary remote version control systems. |
| Vesta | Networking is inherent to the system. The repository exports both an NFS interface and an RPC interface. The checkout and checkin tools automatically contact a remote repository when required to perform an operation. |
| Visual SourceSafe | VSS uses a Windows network share which has to be writable for the VSS users (since this means doubling maintenance for new users). Add user in VSS and to share permissions. the share is most often world-writable, as is the default when creating a share) It does not perform well over a slow network connection. |
How portable is the version-control system to various operating systems, computer architectures, and other types of systems?
| CVS | Good. Client works on UNIX, Windows and Mac OS. Server works on UNIXes and on Windows with a UNIX emulation layer. |
| Aegis | Medium. The source is portable across all UNIXes, but the Windows version work only using cygwin, and even then not entirely natively. |
| Arch | Good. The source is portable across all UNIXes, but requires a UNIX emulation layer on Windows. (need to verify). A service can be hosted on any platform that sports a suitable Internet service. |
| BitKeeper | Very good. Binaries are available for most common UNIX systems and for Windows 98 and above. |
| CMSynergy | Very good - various flavours of Unix, Windows (only NT family for the server), VMS, and possibly other systems. |
| Co-Op | Windows only: starting with Win95. |
| Darcs | Very good. Supports many UNIXes, Mac OS X, and Windows, and is written in a portable language. |
| Monotone | Excellent. Executable is portable across all UNIXes and Win32. |
| OpenCM | Good. Portable across all UNIX systems. |
| Perforce | Excellent. Runs on UNIX, Mac OS, BeOS and Windows. |
| Subversion | Excellent. Clients and Servers work on UNIX, Windows and Mac OS X. |
| svk | Good. Clients requires subversion and its perl bindings. |
| Vesta | Good. It should be portable to any UNIX system. Currently it runs on Digital/Compaq/HP Tru64 UNIX and Linux on several different CPU architectures. Ports to Solaris and FreeBSD are planned but haven't begun yet. |
| Visual SourceSafe | The Microsoft Product is Windows only. MainSoft ships a version of it for some UNIX platforms. |
Does the system have a WWW-based interface that can be used to browse the tree and the various revisions of the files, perform arbitrary diffs, etc?
| CVS | Yes. WebCVS, ViewCVS, and Chora. |
| Aegis | Yes. |
| Arch | There's ViewARCH, and ArchZoom which are works in progress. |
| BitKeeper | Yes. Its own built-in web-interface. |
| CMSynergy | Possibly. |
| Co-Op | Since this functionality is always available locally, there is no need for web interface. |
| Darcs | darcs.cgi is included in the distribution. |
| Monotone | No. |
| OpenCM | No. |
| Perforce | Yes, P4Web. |
| Subversion | Yes. ViewCVS, SVN::Web, WebSVN, ViewSVN, mod_svn_view and Chora. Aside from that, the Subversion Apache service provides a rudimentary web-interface. |
| svk | Yes. Same as Subversion. |
| Vesta | Yes: Vestaweb. |
| Visual SourceSafe | It is possible to code one using the API, but no official or third-party one exists. |
What is the availability of graphical user-interfaces for the system? How many GUI clients are present for it?
| CVS | Very good. There are many available GUIs: WinCVS, Cervisia (for KDE), ViewCVS (web-based), TortoiseCVS (Windows Explorer plug-in). |
| Aegis | There is tkaegis. |
| Arch | There is tlator, Octopy and possibly others under development. |
| BitKeeper | Good. BitKeeper ships with several GUIs for performing common tasks. I'm not aware of any third-part GUIs. |
| CMSynergy | A couple of GUIs. A motif-based one (even on Windows) allows most functionality but is clunky. A nicer Java one allows developer work but not much administrative stuff. Has an SCCI plug-in, though it doesn't handle network problems well. |
| Co-Op | The system is GUI-based by design. |
| Darcs | None to speak of. (There is a modest graphical interface to a few commands in the distribution, but it is not being developed currently.) |
| Monotone | No GUIs are available. |
| OpenCM | No GUIs are avialable. |
| Perforce | Yes, P4Win and others based on the available libp4 library. |
| Subversion | Very good. There are many available GUIs: RapidSVN (cross-platform), ViewCVS (web), TortoiseSVN (Windows Explorer plug-in), Jsvn (Java), etc. Most of them are still under development. |
| svk | No GUIs are available. |
| Vesta | No GUIs are available, but the repository has a C++ API, and it's not be hard to write one. (At least three different project-specific ones have been written by users at Compaq and Intel.) |
| Visual SourceSafe | Standalone GUI comes with it, plus SCCI plug-in for MS Visual Developer Studio. There is an Eclipse plug-in. |
What are the licensing terms for the software?
| CVS | GNU GPL (open source) |
| Aegis | GNU GPL (open source) |
| Arch | GNU GPL (open source) |
| BitKeeper | Proprietary, binary only license. Comes in two versions: gratis and pay per use. The gratis license is intended for development of free software only and is problematic. The pay per use license is free of most of its problems. |
| CMSynergy | Prices negotiable with salesman. Server is typically roughly 20,000 British Pounds. Clients are 4,000 British Pounds. Per-year costs of 18% of original. |
| Co-Op | Proprietary, short text key. 30-day full-featured trial. Free to "observers" (members who don't make changes). $159 per workstation. |
| Darcs | GNU GPL (open source) |
| Monotone | GNU GPL (open source) |
| OpenCM | GNU GPL (open source), but moving soon to BSD or CPL (also open source). |
| Perforce | A proprietary, binary only, commercial license. Price starting at $750 per seat for the first year and then $150 for continuing support for the subsequent years. Free for Open Source projects (no support in this case). |
| Subversion | Apache/BSD-style license. (open-source) |
| svk | Perl License. (open source) |
| Vesta | GNU LGPL (open source) |
| Visual SourceSafe | VSS Ships with MSDN, and can also be purchased stanalone or with other tools. |