Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Stack Overflow
Q&A for professional and enthusiast programmers
Software Recommendations
Q&A for people seeking specific software recommendations
Pets
Q&A for pet owners, caretakers, breeders, veterinarians, and trainers
Ask Ubuntu
Q&A for Ubuntu users and developers
Area 51
Q&A for proposing new sites in the Stack Exchange network
Super User
Q&A for computer enthusiasts and power users
English Language Learners
Q&A for speakers of other languages learning English
Stack Apps
Q&A for apps, scripts, and development with the Stack Exchange API
Server Fault
Q&A for system and network administrators
Information Security
Q&A for information security professionals
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Community Building
Q&A for community managers, administrators, and moderators
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Game Development
Q&A for professional and independent game developers
Bicycles
Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Drupal Answers
Q&A for Drupal developers and administrators
User Experience
Q&A for user experience researchers and experts
Academia
Q&A for academics and those enrolled in higher education
Web Applications
Q&A for power users of web applications
MathOverflow
Q&A for professional mathematicians
Physics
Q&A for active researchers, academics and students of physics
Computer Science
Q&A for students, researchers and practitioners of computer science
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Mathematica
Q&A for users of Wolfram Mathematica
Chemistry
Q&A for scientists, academics, teachers, and students in the field of chemistry
Magento
Q&A for users of the Magento e-Commerce platform
Lifehacks
Q&A for people looking to bypass life's everyday problems with simple tricks
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Code Review
Q&A for peer programmer code reviews
Travel
Q&A for road warriors and seasoned travelers
Mathematics
Q&A for people studying math at any level and professionals in related fields
Biology
Q&A for biology researchers, academics, and students
Ask Patents
Q&A for people interested in improving the patent system
Open Data
Q&A for developers and researchers interested in open data