ArtRage's software license is like other software licenses. It gives you the right to use ArtRage on one computer. If you want to use ArtRage on more than one computer you need to purchase another license.
This is how all software licenses work. You have purchased multiple licenses for your operating system (Windows or MacOSX), your other graphics applications, and so on.
Installing ArtRage 2.5 with the same license key on more than one computer will also cause you problems when updating.
And dewd, it's only 25 bux. It's not like we're stinging you $200+ for every computer you want to install it on.
AndyRage's mantra for graphics engine code:
"Sure - how hard can it be?"