Subversion is a mature open source version control system used by many open source projects, including Apache Software Foundation, KDE, GNOME, Free Pascal, GCC, Python, Django, Ruby, and Mono. Its developers have just released version 1.5. Subversion is version control system originally designed to replace CVS, which many felt had important limitations.
Although Subversion did provoke a "branching model" war in some quarters, it also brought significant improvements over CVS, according to some practitioners:
- Directory and file renaming: restructuring source code tree is easy, without losing version traceability.
- Checked-out directories are 'clean' (no CVS directories).
- File caching allows more actions in "disconnected" state.
- Atomic commits.
- Log-per-commit.
- Improved speed.
- Better handling of BIN (binary) files.
- A community of active developers.
Subversion can use the HTTP-based WebDAV/DeltaV protocol for network communications, and the Apache web server to provide repository-side network service. This gives Subversion an advantage over CVS in interoperability, and provides various key features for free: authentication, wire compression, and basic repository browsing. However, Subversion also offers a "svnserv" standalone server option using a custom protocol, and can be tunnelled over ssh. And, although it is open source software, commercial support is available.
The Big Picture from the Subversion Developer Intro
Version 1.5 introduces a number of new features, among them:
- Merge tracking: allows the user to see what changes have been merged and on which branches they have been merged. The goal is to reduce the effort involved in moving changes between branched (i.e. 1.0, 1.1 and main development).
- Sparse checkouts: allows developers with very large source trees to get only subsets of their code to their machine.
- Interactive Conflict Resolution: support for conflict resolution in the command line client and api hooks exposing that support for other clients.
- Changelist support: allows developers to name groups of files as a single changelist. This can be useful when the developer is working on more than one problem at the same time.
- Enhancements to Copy and Move operations.
A new version the Eclipse plugin for Subversion (Subclipse) has also been released. Other clients include: TortiseSVN (a windows shell extension), RapidSVN (a rich client) and AnkhSVN (a Visual Studio plugin).