Donateware (or donationware) is a form of software distribution. Distributed as freeware, donateware stipulates that the user must donate to a charitable cause in order to "register" the software. Sometimes the author of the program stipulates which charity the user must donate to, sometimes they just suggest one, and sometimes the author leaves the choice up to the user. Normally the user does not need to contact the author with any information in order to "register" their program—it is implicit with the donation (registering does not "unlock" any extra features). The donation stipulation is little more than a gimmick since the program's author cannot verify whether or not the user made any such donation. Therefore, donateware can be thought of as "freeware with a reminder to be charitable."
Predictably, this form of software distribution is very uncommon. One of the early versions of donateware was Screenpeace , a screen saver for Microsoft Windows 3.0. The suggested charity was Greenpeace, though any other charity qualified.
A variation of Donateware is where the author requests user donation to a designated charity to legally use the software after a trial period. After verification of the donation, author sends user a registration code to disable popup reminder messages. A current example is MJ's CD Archiver, a file archiver for Microsoft Windows/Linux/Mac OS X. The suggested charity is NACEF, a USA-registered charity for China's Project Hope.
Another form of Dontationware is when the author makes the software fully functional and free but request (sometimes loudly) that you really should donate to the software creator whatever you feel is proper. Spybot falls under this category.