The couple donates $1 million to support a Washington state initiative that would require criminal background checks on firearm sales at gun shows and online.
The co-founder of Microsoft and his wife donated $2.65 billion last year in an effort to combat deadly diseases around the world.
Facebook CEO Mark Zuckerberg saw the biggest jump in wealth among all the people on the list, earning him the No. 11 spot.
Genetically modified bananas loaded with vitamin A are scheduled to go into human trials in the US with the aim of improving nutrition in Africa.
Bill Gates has transformed from man to Lego to share the best books he read in 2014, including one published in the '60s and one that's not yet released.
Bill Gate reemerges on Reddit to share an unusual image that ties into his work through the Bill & Melinda Gates Foundation.
Now that even Tim Cook is pouring ice water over his head to support ALS, Bill Gates shows that he's still smarter than everyone else.
Stock sale puts Gates in second, behind fellow former CEO Steve Ballmer.
Appearing on CBS News, the former Microsoft CEO also says that Microsoft didn't fail at mobile, but merely got the formula wrong.
In a Bloomberg interview, Microsoft co-founder says once Apple gets involved in a new technology -- in this case, mobile payments -- it has more chance of gaining critical mass.