Stack Overflow
Q&A for professional and enthusiast programmers
Drupal Answers
Q&A for Drupal developers and administrators
Server Fault
Q&A for system and network administrators
Information Security
Q&A for information security professionals
WordPress Development
Q&A for WordPress developers and administrators
Physics
Q&A for active researchers, academics and students of physics
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Ask Different
Q&A for power users of Apple hardware and software
Area 51
Q&A for proposing new sites in the Stack Exchange network
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Web Applications
Q&A for power users of web applications
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Video Production
Q&A for engineers, producers, editors and enthusiasts spanning the fields of video and media creation
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Mathematics
Q&A for people studying math at any level and professionals in related fields
User Experience
Q&A for user experience researchers and experts
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Homebrewing
Q&A for dedicated home brewers and serious enthusiasts
Bitcoin
Q&A for Bitcoin users, developers, and enthusiasts
Academia
Q&A for academics and those enrolled in higher education
Beer, Wine & Spirits
Q&A for alcoholic beverage aficionados and those interested in beer, wine, or spirits
Biology
Q&A for biology researchers, academics, and students
Data Science
Q&A for Data science professionals, Machine Learning specialists, and those interested in learning more about the field
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
Open Data
Q&A for developers and researchers interested in open data