Cool stuff. I think there were a few similar efforts going on. For example, LSP was based on the protocol developed for OmniSharp, which was an open source .NET-specific implementation started in like 2013 by a Vim fanatic.
Interesting! Is there a source for that? I remember OmniSharp. It was a blessing when I could start to use vim when I had to use .NET a few years ago. I had no idea that's what LSP grew out of.
The history article above says that OmniSharp started out on Roslyn, but actually it originally used NRefactory. The old server is here: https://github.com/OmniSharp/omnisharp-server
