Mathematics
Q&A for people studying math at any level and professionals in related fields
Physics
Q&A for active researchers, academics and students of physics
Linguistics
Q&A for professional linguists and others with an interest in linguistic research and theory
History of Science and Mathematics
Q&A for people interested in the history and origins of science and mathematics
Stack Overflow
Q&A for professional and enthusiast programmers
Politics
Q&A for people interested in governments, policies, and political processes
Chemistry
Q&A for scientists, academics, teachers, and students in the field of chemistry
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Quantum Computing
Q&A for engineers, scientists, programmers, and computing professionals interested in quantum computing
Theoretical Computer Science
Q&A for theoretical computer scientists and researchers in related fields
Super User
Q&A for computer enthusiasts and power users
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
The Great Outdoors
Q&A for people who love being outdoors enjoying nature and wilderness, and learning about the required skills and equipment
Code Review
Q&A for peer programmer code reviews
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Web Applications
Q&A for power users of web applications
Mathematica
Q&A for users of Wolfram Mathematica
Astronomy
Q&A for astronomers and astrophysicists
Biology
Q&A for biology researchers, academics, and students
Computer Science
Q&A for students, researchers and practitioners of computer science
Psychology & Neuroscience
Q&A for practitioners, researchers, and students in cognitive science, psychology, neuroscience, and psychiatry
Earth Science
Q&A for those interested in the geology, meteorology, oceanography, and environmental sciences
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Puzzling
Q&A for those who create, solve, and study puzzles
Mathematics Educators
Q&A for those involved in the field of teaching mathematics
Ask Different
Q&A for power users of Apple hardware and software
MathOverflow
Q&A for professional mathematicians
French Language
Q&A for students, teachers, and linguists wanting to discuss the finer points of the French language
Skeptics
Q&A for scientific skepticism
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
Chess
Q&A for serious players and enthusiasts of chess
Travel
Q&A for road warriors and seasoned travelers
Mi Yodeya
Q&A for those who base their lives on Jewish law and tradition and anyone interested in learning more
Movies & TV
Q&A for movie and TV enthusiasts
Ethereum
Q&A for users of Ethereum, the decentralized application platform and smart contract enabled blockchain
Interpersonal Skills
Q&A for people looking to improve their interpersonal communication skills
Music Fans
Q&A for music historians, critics, and fans