NET specific features, not strictly IDEs.
Later the OmniSharp OSS project came along and added intellisense to a half-dozen editors with its smart out of process intellisense server but these code editors with. Xamarin Studio came out in 2013 as a standalone IDE for mobile app development, but wasn't a generalized or web development IDE. NET development on a Mac was resigned to Mono and whatever text editor you knew how to exit successfully.
