Mathematics
Q&A for people studying math at any level and professionals in related fields
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Law
Q&A for legal professionals, students, and others with experience or interest in law
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Mathematics Educators
Q&A for those involved in the field of teaching mathematics
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Academia
Q&A for academics and those enrolled in higher education
Economics
Q&A for those who study, teach, research and apply economics and econometrics
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Computational Science
Q&A for scientists using computers to solve scientific problems
History
Q&A for historians and history buffs
Puzzling
Q&A for those who create, solve, and study puzzles
Super User
Q&A for computer enthusiasts and power users
History of Science and Mathematics
Q&A for people interested in the history and origins of science and mathematics
Politics
Q&A for people interested in governments, policies, and political processes
Skeptics
Q&A for scientific skepticism
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Board & Card Games
Q&A for people who like playing board games, designing board games or modifying the rules of existing board games
Arqade
Q&A for passionate videogamers on all platforms
Retrocomputing
Q&A for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear