I downloaded and extracted it. Note that the page says you need to install Mono (it says "last version of mono distributive"). Trying to start it by running the exe in terminal will tell you the files you need like so:
The assembly mscorlib.dll was not found or could not be loaded.
It should have been installed in the `/usr/lib/mono/2.0/mscorlib.dll' directory.
Then I googled and found this: On stackoverflow
. I ran this:
sudo apt-get install mono-complete
and then when all done, run in terminal from the folder where SMath is extracted:
and it will pop right up.
I am running Ubuntu 14.04 (which coincides with the Zorin 9 coming out) but Zorin 8 (Ubuntu 12.04) should work similarly I think.