Ask HN: Is there a platform for helping people through programming/developing?

How can a programmer help people in developing/poor countries? I know open-source is very social and so on, but most of it gets used in commercial products (I know, I know, not all of it) and helps mostly developed countries (conjecture).

So my question: is there a platform or organization, where social projects are gathered for people to help in their spare (or full) time?