Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems.
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Ask Different
Q&A for power users of Apple hardware and software
Theoretical Computer Science
Q&A for theoretical computer scientists and researchers in related fields
Programmers
Q&A for professional programmers interested in conceptual questions about software development
Server Fault
Q&A for professional system and network administrators
Mathematics
Q&A for people studying math at any level and professionals in related fields
Meta Stack Overflow
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Programming Puzzles & Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Computational Science
Q&A for scientists using computers to solve scientific problems
Area 51
Stack Exchange Network staging zone, where users come together to build new Q&A sites
