T4 without Visual Studio?
.net, t4
Solution
I wrote a cleanly reverse-engineered implementation of a T4 engine for the MonoDevelop IDE. It's open-source, licensed under the permissive MIT/X11 license, so you are free to embed the engine in your app or redistribute it. There's also an implementation of the TextTransform.exe command-line tool available as a dotnet global tool, and some APIs in the Mono.TextTemplating namespace to aid in hosting the engine.
You can get packages from NuGet and the source is on GitHub.
Problem
I'm trying to wireup some code gen templates to my team's automated build process. Our SCM team doesn't want Visual Studio on our build machine (which I have a hard time arguing with). Is there a way to install the T4 engine without Visual Studio?