Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Server Fault
Q&A for system and network administrators
Super User
Q&A for computer enthusiasts and power users
Stack Overflow
Q&A for professional and enthusiast programmers
Area 51
Q&A for proposing new sites in the Stack Exchange network
Information Security
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Motor Vehicle Maintenance & Repair
Q&A for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Theoretical Computer Science
Q&A for theoretical computer scientists and researchers in related fields
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
Ask Ubuntu
Q&A for Ubuntu users and developers
Web Applications
Q&A for power users of web applications
Stack Apps
Q&A for apps, scripts, and development with the Stack Exchange API
Physical Fitness
Q&A for physical fitness professionals, athletes, trainers, and those providing health-related needs
Photography
Q&A for professional, enthusiast and amateur photographers
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Computer Science
Q&A for students, researchers and practitioners of computer science