Noticed this on MSFN:
https://github.com/itsmattkc/dotnet9x

This project is a work-in-progress backport of .NET Framework 2.0 - 3.5 to Windows 9x. Currently 2.0 is believed to be largely functional while work on 3.5 has just begun.

Officially, .NET Framework 3.5 never supported anything below XP, and .NET in general never supported 95. This project changes that, backporting CLR 2.0 to 95 and Framework 3.5 to 9x.