I normally do a much deeper dive into the existing ecosystem before I write a library like this. In this case, I tried a few of the popular packages, but in the end decided my own pursuit of the exact types I wanted was more interesting. So, I just went for it.
I've been playing around with some of the "standard/common monads in C# for a while now, in OSS (https://github.com/pimbrouwers/Danom) and at work. It's awesome. I can't imagine working without them anymore.
Our shop converted 6 years ago, from C# to exclusively F#. I also author and maintain some packages (falco, donald, validus and others). The language is tough to learn if you're coming from a C-style language. But worth the effort and experience. It's extremely concise a true delight to build programs in that are fast, robust and durable.
There are a few drawbacks, depending on your perspective:
- compilation is slower than c# and hot reload isn't supported (it's in progress)
- there are very few opportunities to use it professionally