Microsoft offers the VSSConverter tool for conversion of Visual SourceSafe projects to TFS. The VSSConverter tool is sufficient for small and simple VSS projects but you may want to consider the CS-Converter tool for converting larger, more complex VSS projects.

The advantages of CS-Converter over Microsoft VSSConverter are:

• Shared files support - VSSConverter duplicates VSS-shared files in the TFS repository, i.e., changes performed to one converted file don't affect the duplicated files. CS-Converter allows you to retain VSS-shared files relations and automatically replicates changes performed on one file to all shared files.
• Conversion integrity - VSSConverter doesn't support conversion verification. CS-Converter verifies the conversion results and suggests fixes whenever the converted file doesn't match the origin file.
• Changesets timestamp - VSSConverter creates the TFS changesets with the current date. CS-Converter supports creation of TFS changesets with the original check-in date.
• Pinned revisions support - In VSS, revisions checked-in after a "pinned" revision are usually unstable revisions. VSSConverter converts these revisions as normal revisions. CS-Converter enables you to create a new branch for these revisions. (You can merge the branch to the trunk anytime.)
• Synchronization Mode - CS-Converter allows you to continue using either or both version control systems, TFS and VSS, concurrently even after conversion. Versions added on one system can be updated to the other. This feature allows for a smoother transition form your old system to TFS.
• User friendly - VSSConverter is a command line tool with XML configuration files. CS-Converter includes an intuitive GUI that allows easy configuration. Additionally, the progress and status of the conversion are available at any point.
• Username mapping - VSSConverter requires you to specify the VSS-to-TFS user mapping in an XML file. CS-Converter displays all VSS and TFS user names and allows you to graphically assign the mapping.

If you have already converted projects to TFS by using the VSSConverter tool, you may still benefit from CS-Converter.