Episode and Mountain Lion?

I don't know for certain but Episode has a great track record for me as far as not breaking when a new OS is released.

I've been using v. 5 for a long time and I believe through three major versions of OS X (10.4, 10.5, 10.6).

I'm sure that if there are compatibility issues they will be fixed up quickly as their support seems really responsive. I'm guessing they are well aware of Mountain Lion as it hasn't been a secret for quite some time now. :-)

As usual, it is a good time to remember that if you use your machine (and a particular piece of software) to make your living that it is generally bad to update blindly without double-checking compatibility with your most important applications. Apple's .0 releases are infamous for having issues, so I would also recommend cloning your system to another drive and installing the update on there to test it out for a while. There is no uninstalling an OS X update so make sure you can return to a working system just in case you run into problems.

-Matt