Donations to TM++ are optional. Donation will be used for to buy hardware, to pay for other project-related resources, or to pay for other necessities like promotional activities etc. Making a OS portable library is expensive, currently I compile on Debian, Mac OS X, Windows(R), and Ubuntu, but I would like to get a fully working distributed build system up and running with even more OS's. 5% of your donation goes automatically to SourceForge.net, and %5 to Open Source Initiative (OSI).