Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Stack Overflow
Q&A for professional and enthusiast programmers
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Bioinformatics
Q&A for researchers, developers, students, teachers, and end users interested in bioinformatics
Coffee
Q&A for people interested in all aspects of producing and consuming coffee
Mathematics
Q&A for people studying math at any level and professionals in related fields
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Physics
Q&A for active researchers, academics and students of physics
Puzzling
Q&A for those who create, solve, and study puzzles
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
The Workplace
Q&A for members of the workforce navigating the professional setting
Code Review
Q&A for peer programmer code reviews
Politics
Q&A for people interested in governments, policies, and political processes
Super User
Q&A for computer enthusiasts and power users
Computer Graphics
Q&A for computer graphics researchers and programmers