Arqade
Q&A for passionate videogamers on all platforms
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Japanese Language
Q&A for students, teachers, and linguists wanting to discuss the finer points of the Japanese language
Stack Overflow
Q&A for professional and enthusiast programmers
Ask Different
Q&A for power users of Apple hardware and software
Board & Card Games
Q&A for people who like playing board games, designing board games or modifying the rules of existing board games
Area 51
Q&A for proposing new sites in the Stack Exchange network
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Community Building
Q&A for community managers, administrators, and moderators
Super User
Q&A for computer enthusiasts and power users
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Game Development
Q&A for professional and independent game developers
Pets
Q&A for pet owners, caretakers, breeders, veterinarians, and trainers
User Experience
Q&A for user experience researchers and experts
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts