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
Arqade
Q&A for passionate videogamers on all platforms
Information Security
Q&A for information security professionals
Stack Overflow
Q&A for professional and enthusiast programmers
Academia
Q&A for academics and those enrolled in higher education
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
Network Engineering
Q&A for network engineers
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Retrocomputing
Q&A for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear
Area 51
Q&A for proposing new sites in the Stack Exchange network
Computer Science Educators
Q&A for those involved in the field of teaching Computer Science
Photography
Q&A for professional, enthusiast and amateur photographers
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Bicycles
Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Space Exploration
Q&A for spacecraft operators, scientists, engineers, and enthusiasts
Game Development
Q&A for professional and independent game developers
Music: Practice & Theory
Q&A for musicians, students, and enthusiasts
Open Source
Q&A for people organizing, marketing or licensing open source development projects
Software Recommendations
Q&A for people seeking specific software recommendations
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Biology
Q&A for biology researchers, academics, and students
Earth Science
Q&A for those interested in the geology, meteorology, oceanography, and environmental sciences
German Language
Q&A for speakers of German wanting to discuss the finer points of the language and translation
Quantum Computing
Q&A for engineers, scientists, programmers, and computing professionals interested in quantum computing
Sound Design
Q&A for sound engineers, producers, editors, and enthusiasts
Mathematics Educators
Q&A for those involved in the field of teaching mathematics
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Personal Finance & Money
Q&A for people who want to be financially literate
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Mathematics
Q&A for people studying math at any level and professionals in related fields
Graphic Design
Q&A for Graphic Design professionals, students, and enthusiasts
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Physics
Q&A for active researchers, academics and students of physics
Puzzling
Q&A for those who create, solve, and study puzzles
Vi and Vim
Q&A for people using the vi and Vim families of text editors
Lifehacks
Q&A for people looking to bypass life's everyday problems with simple tricks
The Workplace
Q&A for members of the workforce navigating the professional setting
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Arduino
Q&A for developers of open-source hardware and software that is compatible with Arduino
English Language Learners
Q&A for speakers of other languages learning English
Computer Science
Q&A for students, researchers and practitioners of computer science
Blender
Q&A for people who use Blender to create 3D graphics, animations, or games
Ebooks
Q&A for ebook publishers and readers
User Experience
Q&A for user experience researchers and experts
Ask Different
Q&A for power users of Apple hardware and software
Seasoned Advice
Q&A for professional and amateur chefs
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
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
Code Review
Q&A for peer programmer code reviews
Project Management
Q&A for project managers
Interpersonal Skills
Q&A for people looking to improve their interpersonal communication skills
Music Fans
Q&A for music historians, critics, and fans