Primarily a programmer, but interested in gaming, mathematics, physics, and linguistics as well.
Stack Overflow
Q&A for professional and enthusiast programmers
Super User
Q&A for computer enthusiasts and power users
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Mathematics
Q&A for people studying math at any level and professionals in related fields
Arqade
Q&A for passionate videogamers on all platforms
English Language Learners
Q&A for speakers of other languages learning English
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Science Fiction & Fantasy
Q&A for science fiction and fantasy enthusiasts
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Latin Language
Q&A for linguists, teachers, and students wanting to discuss the finer points of the Latin language
Computer Graphics
Q&A for computer graphics researchers and programmers
MathOverflow
Q&A for professional mathematicians
Code Review
Q&A for peer programmer code reviews
Computer Science
Q&A for students, researchers and practitioners of computer science
Puzzling
Q&A for those who create, solve, and study puzzles
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Information Security
Q&A for information security professionals
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Physics
Q&A for active researchers, academics and students of physics
Game Development
Q&A for professional and independent game developers
Open Data
Q&A for developers and researchers interested in open data
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Astronomy
Q&A for astronomers and astrophysicists
Salesforce
Q&A for Salesforce administrators, implementation experts, developers and anybody in-between
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
History
Q&A for historians and history buffs
Computer Science Educators
Q&A for those involved in the field of teaching Computer Science
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Music: Practice & Theory
Q&A for musicians, students, and enthusiasts
Mathematica
Q&A for users of Wolfram Mathematica
Mi Yodeya
Q&A for those who base their lives on Jewish law and tradition and anyone interested in learning more
Mathematics Educators
Q&A for those involved in the field of teaching mathematics
Photography
Q&A for professional, enthusiast and amateur photographers
Open Source
Q&A for people organizing, marketing or licensing open source development projects
Computational Science
Q&A for scientists using computers to solve scientific problems
Graphic Design
Q&A for Graphic Design professionals, students, and enthusiasts
Retrocomputing
Q&A for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear
Blender
Q&A for people who use Blender to create 3D graphics, animations, or games
User Experience
Q&A for user experience researchers and experts
Academia
Q&A for academics and those enrolled in higher education
Biology
Q&A for biology researchers, academics, and students
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Parenting
Q&A for parents, grandparents, nannies and others with a parenting role
Server Fault
Q&A for system and network administrators
Linguistics
Q&A for professional linguists and others with an interest in linguistic research and theory
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Motor Vehicle Maintenance & Repair
Q&A for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles
Personal Finance & Money
Q&A for people who want to be financially literate
Psychology & Neuroscience
Q&A for practitioners, researchers, and students in cognitive science, psychology, neuroscience, and psychiatry
Chinese Language
Q&A for students, teachers, and linguists wanting to discuss the finer points of the Chinese language
The Workplace
Q&A for members of the workforce navigating the professional setting
German Language
Q&A for speakers of German wanting to discuss the finer points of the language and translation
Russian Language
Q&A for students, teachers, and linguists wanting to discuss the finer points of the Russian language
Seasoned Advice
Q&A for professional and amateur chefs
Politics
Q&A for people interested in governments, policies, and political processes
Law
Q&A for legal professionals, students, and others with experience or interest in law
Video Production
Q&A for engineers, producers, editors and enthusiasts spanning the fields of video and media creation
Interpersonal Skills
Q&A for people looking to improve their interpersonal communication skills
Programming Language Design and Implementation
Q&A for designers and implementers of computer programming languages
Web Applications
Q&A for power users of web applications