Richard Stallman, founder of the Free Software Foundation, says people are paying too much attention to the retirement of Microsoft Chairman and co-founder Bill Gates.

Gates, the third-richest person in the world, retired in June. Stallman said in a recent BBC article that people should pay attention to "the unethical system of restrictions that Microsoft, like many other software companies, imposes on its customers," instead of paying attention to the leadership of the software company.

The criticism is the latest clash in Stallman's long-running crusade against restrictions that prevent software from being shared, modified, and distributed without a license. He criticized the software company for lack of interoperability and said it seems that the main advance Windows Vista made was to increases user restrictions.

However, Stallman did not limit his critique to proprietary software. In addition to accusing Microsoft of persistently engaging in anti-competitive behavior, he targeted the philanthropist's efforts to help the poor.

Stallman cited the L.A. Times and said only five to 10% of the money from the Bill & Melinda Gates Foundation funds causes, and the remainder is invested, "sometimes in companies it suggests cause environmental degradation and illness in the same poor countries."

Stallman's fight for free software has been personal for years now. The founder of the GNU Project and Free Software Foundation took aim at Gates about three years ago, when Gates defended software patents and used the term "communist" to characterize those who oppose proprietary software. Stallman has named Microsoft, as well as Apple and other software companies, while criticizing the proprietary system that he says equates acts of sharing with attacking a ship.