- Development status: Maintained
- Repository model: Client-server
- Concurrency model: Merge
Microsoft Visual SourceSafe (VSS) is a source control software package oriented towards small software development projects. Like most source control systems, SourceSafe creates a virtual library of computer files. While most commonly used for source code, SourceSafe can actually handle any type of file in its database, but prior versions have been shown to be unstable when confronted with large amounts of non-textual data (images, binary executables, etc.).
SourceSafe was originally created by a company called One Tree Software. One Tree SourceSafe had gone through several releases in their 1.x to 2.x cycles, supporting DOS, OS/2 (with a Presentation Manager GUI), Windows, Windows NT, Mac, and Unix. When Microsoft bought OneTree in 1994, they immediately ceased development on all versions except for Windows. Microsoft "Visual SourceSafe 3.1", a Windows 16-bit-only, rebranded One Tree 3.0 version, was briefly available before Microsoft released a Version 4.0.
SourceSafe was initially not a client/server SCM, but rather a local only SCM. Architecturally, this serves as both a strength and weakness of design, depending on the environment it is used in. It allows a single user system