Stack Overflow

stack overflow, part of stack exchange , is a free, community-driven, reputation-based q & a site for computer programmers.

Free Android iPhone Web

Quora

Quora.com is a question/answer service allowing users to pose questions that other users can answer, each question and answer can have comments, each users can write one individual answer and there can be a summary answer.

Free Android iPhone Web

Answers

Answers is the place to go to ask questions and receive answers from the community at large on any topic. Connect with people who know the answers to your questions...

Free iPhone