Help downloading/installing a .tar program.

I need help downloading this art software.

The art program;
http://code.google.com/p/grafx2/


Whenever I click it from my recent downloads, it goes straight to my Zipeg program. I extracted it but nothing happens now when I click on the program. Help?

I have a Macbook pro, a 10.6.8.

 

I downloaded The Grafx2 App and let OS X's own Archive Utility open the file and all is well.

 

Oh, thank you! Automatic Zipeg messed me up there. I'm new to macs, is it obvious? Thanks again!