Bill Gates has donated over $36,854,000,000 in his lifetime 13 years ago
An interesting, speculative discussion would be to examine if the harm (if any) that came from Microsoft's monopolistic activities is out-valued by the good done by Gates in his foundation.
Where would the value captured by Microsoft and Gates have been redirected if MS didn't have a monopoly on the PC industry until recently? My guess is not fighting tropical diseases- but where?