Some proprietary Linux software

If it makes you feel better, then by all means, pay for software. Wish there was some way of rewarding developers with something other than cold hard cash. Then they wouldn't feel the need to put up barriers. We've covered ways of doing this before, like Flattr, or the Ransom Model. BTW both applications below are completely out of the price range of people living in the developing world.

Two commercial, closed-source packages which run on Linux:

Softmaker Office 2011

Guitar Pro 6 The linux version is available as a shareware trial.