Stack Overflow
Q&A for professional and enthusiast programmers
Linguistics
Q&A for professional linguists and others with an interest in linguistic research and theory
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
History
Q&A for historians and history buffs
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Super User
Q&A for computer enthusiasts and power users
Skeptics
Q&A for scientific skepticism
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
Physical Fitness
Q&A for physical fitness professionals, athletes, trainers, and those providing health-related needs
Web Applications
Q&A for power users of web applications
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Travel
Q&A for road warriors and seasoned travelers
Area 51
Q&A for proposing new sites in the Stack Exchange network
Code Review
Q&A for peer programmer code reviews
User Experience
Q&A for user experience researchers and experts
Physics
Q&A for active researchers, academics and students of physics
Mathematics
Q&A for people studying math at any level and professionals in related fields
Information Security
Q&A for information security professionals
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Photography
Q&A for professional, enthusiast and amateur photographers
Seasoned Advice
Q&A for professional and amateur chefs
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Server Fault
Q&A for system and network administrators
The Workplace
Q&A for members of the workforce navigating the professional setting
Ask Ubuntu
Q&A for Ubuntu users and developers
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing