Wealthy Microsoft co-founder Paul Allen has taken up his friend Bill Gates' challenge to publicly pledge the majority of his wealth to philanthropy.

Allen, who is 57, said yesterday that he plans to leave the majority of his $13 billion estate to philanthropy to continue the work of his foundation and to fund scientific research. It was also a way of marking the 20th anniversary of the Paul G. Allen Family Foundation, which he started in 1990 and has since given 3,000 grants totaling about $400 million.

His total giving over the years has reached about $1 billion, reflecting eclectic interests in science, the arts and education, including nonprofits he founded: the Allen Institute for Brain Science and the Experience Music Project.

(READ more in the Seattle Times)