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
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Motor Vehicle Maintenance & Repair
Q&A for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Area 51
Q&A for proposing new sites in the Stack Exchange network
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Computer Science
Q&A for students, researchers and practitioners of computer science
Computational Science
Q&A for scientists using computers to solve scientific problems
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
Sports
Q&A for participants in team and individual sport activities
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Movies & TV
Q&A for movie and TV enthusiasts
Stack Apps
Q&A for apps, scripts, and development with the Stack Exchange API
Board & Card Games
Q&A for people who like playing board games, designing board games or modifying the rules of existing board games
Information Security
Q&A for information security professionals
Skeptics
Q&A for scientific skepticism
Artificial Intelligence
Q&A for people interested in conceptual questions about life and challenges in a world where "cognitive" functions can be mimicked in purely digital environment
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Super User
Q&A for computer enthusiasts and power users
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Seasoned Advice
Q&A for professional and amateur chefs
Puzzling
Q&A for those who create, solve, and study puzzles
Game Development
Q&A for professional and independent game developers
English Language Learners
Q&A for speakers of other languages learning English
Mathematics
Q&A for people studying math at any level and professionals in related fields
Photography
Q&A for professional, enthusiast and amateur photographers
Code Review
Q&A for peer programmer code reviews
Arqade
Q&A for passionate videogamers on all platforms