Stack Overflow
Q&A for professional and enthusiast programmers
Astronomy
Q&A for astronomers and astrophysicists
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Physics
Q&A for active researchers, academics and students of physics
Emacs
Q&A for those using, extending or developing Emacs
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Ask Ubuntu
Q&A for Ubuntu users and developers
Computer Science
Q&A for students, researchers and practitioners of computer science
Super User
Q&A for computer enthusiasts and power users
Physical Fitness
Q&A for physical fitness professionals, athletes, trainers, and those providing health-related needs
Code Review
Q&A for peer programmer code reviews
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Puzzling
Q&A for those who create, solve, and study puzzles
Robotics
Q&A for professional robotic engineers, hobbyists, researchers and students
Mathematics
Q&A for people studying math at any level and professionals in related fields
Bitcoin
Q&A for Bitcoin users, developers, and enthusiasts
Software Recommendations
Q&A for people seeking specific software recommendations
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Server Fault
Q&A for system and network administrators
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
DevOps
Q&A for software engineers working on automated testing, continuous delivery, service integration and monitoring, and building SDLC infrastructure
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Engineering
Q&A for professionals and students of engineering
Hardware Recommendations
Q&A for people seeking specific hardware recommendations