I had a similar reaction when I came across it 4 months ago. I spent an hour or two refactoring it, including turning it into a valid Ruby gem.
PR here: https://github.com/Reactive-Extensions/Rx.rb/pull/1
The pull request sat in limbo until just over a week ago when Matt asked me to sign the Microsoft open source contributor agreement, which I haven't got around to yet.
Unfortunately I don't hold much hope for the library in its current state.