Stack Overflow
Q&A for professional and enthusiast programmers
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Code Review
Q&A for peer programmer code reviews
Home Improvement
Q&A for contractors and serious DIYers
Game Development
Q&A for professional and independent game developers
Engineering
Q&A for professionals and students of engineering
Computer Graphics
Q&A for computer graphics researchers and programmers
Woodworking
Q&A for professional and amateur woodworkers
Computer Science
Q&A for students, researchers and practitioners of computer science
Arqade
Q&A for passionate videogamers on all platforms
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Area 51
Q&A for proposing new sites in the Stack Exchange network
Arduino
Q&A for developers of open-source hardware and software that is compatible with Arduino
Super User
Q&A for computer enthusiasts and power users
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Open Source
Q&A for people organizing, marketing or licensing open source development projects
Mathematics
Q&A for people studying math at any level and professionals in related fields
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Programming Language Design and Implementation
Q&A for designers and implementers of computer programming languages
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Law
Q&A for legal professionals, students, and others with experience or interest in law
Theoretical Computer Science
Q&A for theoretical computer scientists and researchers in related fields
Reverse Engineering
Q&A for researchers and developers who explore the principles of a system through analysis of its structure, function, and operation
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Pets
Q&A for pet owners, caretakers, breeders, veterinarians, and trainers
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Puzzling
Q&A for those who create, solve, and study puzzles
Bicycles
Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles
Interpersonal Skills
Q&A for people looking to improve their interpersonal communication skills
Information Security
Q&A for information security professionals
Anime & Manga
Q&A for anime and manga fans
Physics
Q&A for active researchers, academics and students of physics
User Experience
Q&A for user experience researchers and experts
Travel
Q&A for road warriors and seasoned travelers
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
The Workplace
Q&A for members of the workforce navigating the professional setting
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
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Parenting
Q&A for parents, grandparents, nannies and others with a parenting role
Personal Finance & Money
Q&A for people who want to be financially literate
Biology
Q&A for biology researchers, academics, and students
Academia
Q&A for academics and those enrolled in higher education
The Great Outdoors
Q&A for people who love being outdoors enjoying nature and wilderness, and learning about the required skills and equipment
Japanese Language
Q&A for students, teachers, and linguists wanting to discuss the finer points of the Japanese language
Ask Patents
Q&A for people interested in improving the patent system
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Sports
Q&A for participants in team and individual sport activities
Server Fault
Q&A for system and network administrators