For .NET 3.5: Snippet Compiler Live 2008 Ultimate Edition for Developers (Alpha)
For .NET 2.0 and older: 2.0.8.3 for .NET 2.0 | 2.0.7.1 for .NET 1.1 | Changes | Version 1 | Add-Ins
Many thanks to ActiPro and Skybound (1.1 version only) for donating the editor and toolbar/theming controls, respectively.