I talk with many charities. I also like to ask people about charities where pro bono programming may be especially helpful. If you have ideas, that's great.
A successful example is Benetech.org, a SF Bay Area technology charity that is doing wonderful work in tech and social good; I learned about Benetech because of direct personal advice.
Here are some of my favorite charities in case you're interested in learning more and/or donating. Thank you!
For tech: Apache Software Foundation (ASF), Electronic Frontier Foundation (EFF), Free Software Foundation (FSF), Linux Foundation, Open Source Initiative (OSI), Software Freedom Conservancy (SFC).
For social causes: American Civil Liberties Union (ACLU), Amnesty International, Benetech for Global Literacy, Center for Environmental Health (CEH), Doctors Without Borders, Human Rights Watch (HRW).
No doubt. Paid $100 to ask Andreeesen what his favourite charities are? The SV hero worship is so intense.