Stack Overflow
Q&A for professional and enthusiast programmers
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Retrocomputing
Q&A for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Physics
Q&A for active researchers, academics and students of physics
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Space Exploration
Q&A for spacecraft operators, scientists, engineers, and enthusiasts
Information Security
Q&A for information security professionals
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Law
Q&A for legal professionals, students, and others with experience or interest in law
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Economics
Q&A for those who study, teach, research and apply economics and econometrics
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Bicycles
Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles
Graphic Design
Q&A for Graphic Design professionals, students, and enthusiasts
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
The Great Outdoors
Q&A for people who love being outdoors enjoying nature and wilderness, and learning about the required skills and equipment
Home Improvement
Q&A for contractors and serious DIYers
Engineering
Q&A for professionals and students of engineering
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Internet of Things
Q&A for builders and users of networked sensors and control devices in the contexts of smart homes, industry automation, or environmental sensors
Music: Practice & Theory
Q&A for musicians, students, and enthusiasts
Blender
Q&A for people who use Blender to create 3D graphics, animations, or games
Chemistry
Q&A for scientists, academics, teachers, and students in the field of chemistry
Code Review
Q&A for peer programmer code reviews
German Language
Q&A for speakers of German wanting to discuss the finer points of the language and translation
Web Applications
Q&A for power users of web applications
Photography
Q&A for professional, enthusiast and amateur photographers
Motor Vehicle Maintenance & Repair
Q&A for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
History
Q&A for historians and history buffs
Server Fault
Q&A for system and network administrators
Mathematica
Q&A for users of Wolfram Mathematica
Politics
Q&A for people interested in governments, policies, and political processes
Literature
Q&A for scholars and enthusiasts of literature
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
Academia
Q&A for academics and those enrolled in higher education
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Hardware Recommendations
Q&A for people seeking specific hardware recommendations
Travel
Q&A for road warriors and seasoned travelers