I'm running it in prod since last year and from the runtime perspective there are no issues.

Tooling is what sucks. MonoDevelop F# support is very unreliable. Basic refactoring, like rename, don't work correctly every time and I had to literally do git reset few times, after renaming, as it screw up multiple files.

Also, editor often has visual glitches where letters get corrupted and I have to reopen the file to get it back to normal. Not something I expect from such a long time maintained application. However, it looks like Xamarin Studio 6.0 will be much better.

Alternative is Visual Studio Code with Ionide plugin, but I didn't use that beyond trying it once. Hopefully someone else can comment.

Edit: typos

After my experience, it run smoothly on Linux. I followed the guide at http://www.monodevelop.com/ to install mono, then F#; monodevelop is also a good IDE but personally I use spacemacs with F# layer.

We have several solutions developed in F# over the past year or so that run exclusively on Linux. Mono 4.x has made it an a viable choice for running in production, but the dev experience is still lacking. We develop mostly on Windows with F# power tools plugin. You can find our open-source stuff at https://github.com/Prolucid

It works, although from what I recall the installation wasn't that easy. I think I had to checkout a specific tagged commit instead of the newest master, because the latter had a broken build. Probably works now, it was years ago :)

Im using it on linux, its pretty good in my opinion, im still learning, but packet and stuff like that seems to work fine. Im using it with emacs, so i dont really know how you will fare with other editors.