I'll tag on to this older thread for anyone reading to just mention that it is workable with WINE on linux. I'm specifically using Linux Mint Debian Edition (Mint being an easier switchover from Windows, the Debian counterpart needing fewer frequent upgrades and being open-source iirc).
There are some quirks that arise (no crashing though), and I need to log onto the website on my browser to add custom materials to my account, but beyond that no issues whatsoever. The only thing I'll add is that even if you have an ancient license that you never upgraded I believe CSP has limited machines you can use the license on before you run out. Which SUCKSSSS big time.
Its also easy enough to just fish through your windows install if you set up a dual boot and open .CSP files or whatever they are in the programme on Linux :)
If I weren't already so well acquainted with CSP I'd probably hop to Krita because boooo stinky monetization scheme, but alas. Maybe in the future!