CVS is a version control system, which allows you to keep old versions of files (usually source code), keep a log of who, when, and why changes occurred, etc., like RCS or SCCS. Unlike the simpler systems, CVS does not just operate on one file at a time or one directory at a time, but operates on hierarchical collections of directories consisting of version controlled files. CVS helps to manage releases and to control the concurrent editing of source files among multiple authors. CVS allows triggers to enable/log/control various operations and works well over a wide area network.
ViewVC (formerly known as ViewCVS) is a Python/CGI-based system for viewing and interacting with Subversion and CVS repositories through your Web browser. It can browse directories, view changelogs, generate diffs, view arbitrary revisions, and display annotated ("blame") listings. It has full support for tags and branches, and contains a database-backed query system like Bonsai. It was initially based on the cvsweb work by Henner Zeller, but has been ported to Python and dramatically enhanced.
cvsweb is a visual (WWW) interface for exploring a CVS repository. Its enhancements include recognition and display of popular MIME-types, visual, color-coded, side-by-side diffs of changes, and the ability sort the file display and to hide old files from view. cvsweb requires the server to have CVS and a CVS repository worth exploring.
CVSps collect changesets from CVS repositories. It can be used either by humans to inspect changesets or as an exporter from CVS to other version control systems - it can be told to emit a fast-export stream to standard output. The code has been end-of-lifed and using cvs-fast-export instead is recommended.
OpenGrok is a fast and usable source code search and cross reference engine. It helps you search, cross-reference, and navigate your source tree. It can understand various program file formats and version control histories like Mercurial, Bazaar, Git, ClearCase, Perforce, SCCS, RCS, CVS, or Subversion. In other words, it lets you grok (profoundly understand) the source.
Meld is a visual diff and merge tool. It integrates with most version control systems. The diff viewer lets you edit files in place (diffs update dynamically), and a middle column shows detailed changes and allows merges. The margins show location of changes for easy browsing, and it also features a tabbed interface that allows you to open many diffs at once.
Codestriker is a Web application that supports online code reviews. Traditional document reviews are supported, as well as reviewing diffs generated by an SCM (Source Code Management) system and plain unidiff patches. There are integration points with CVS, Subversion, Clearcase, Perforce, Visual SourceSafe, and Bugzilla. There is a plug-in architecture for supporting other SCMs and issue tracking systems. It minimizes paper work, ensures that issues, comments, and decisions are recorded in a database, and provides a comfortable workspace for actually performing code inspections. An optional highly-configurable metrics subsystem allows you to record code inspection metrics as a part of your process.
Cervisia is a KDE graphical frontend for the CVS client. It features checking out a module from a repository, updating or retrieving the status of a working directory or single files, common operations like add, remove and commit, diff against the repository and between different revisions, annotated view of a file, view of the log messages in tree and list form as well as resolving of conflicts in a file.
Chora is built upon the Horde Application Framework and provides a read-only browser interface to any number of version control repositories. Advanced features include a visual branch view of the repository's history, pretty-printed output, annotation, patchsets and basic statistics.