sz81 only requires SDL and the SDL development headers (they might be in an SDL-dev package) and then all you have to do is type "make". At the moment I mostly use Puppy Linux but I also have a Xubuntu 10.10 installation and I haven't had a problem compiling sz81 on Xubuntu.

If you want sz81 packaged for your particular distribution then possibly there's a dedicated forum thread for package requests on the Ubuntu and Mint official forums. That's what normally happens, and then I'll notice it and link to it from my website.

Hope this helps.

Regards,
Thunor