Source control is a necessary part of any development project. VS.NET provides a basic user interface that can interact with any source control system that implements the Microsoft Source Code Control Interface (MSSCCI). The most common system is Visual Source Safe (VSS), so for this appendix, which will walk you through the basic operations of source control in VS.NET, we will assume you are using VSS Version 6.0d. (The d revision of Version 6.0 was released with VS.NET 2003. This is the only version of VSS that is supported with VS.NET 2003.)