Type to find sites:

Stack Overflow

Q&A for professional and enthusiast programmers

Super User

Q&A for computer enthusiasts and power users

Server Fault

Q&A for system administrators and desktop support professionals

Gaming

Q&A for passionate videogamers on all platforms

Programmers

Q&A for professional programmers interested in conceptual questions about software development

Meta Stack Overflow

Q&A for the Stack Exchange engine powering these sites

Mathematics

Q&A for people studying math at any level and professionals in related fields

Apple

Q&A for power users of Apple hardware and software

English Language and Usage

Q&A for linguists, etymologists, and serious English language enthusiasts

TeX - LaTeX

Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems

Unix and Linux

Q&A for users of Linux, FreeBSD and other Un*x-like operating systems.

WordPress

Q&A for WordPress developers and administrators

Android Enthusiasts

Q&A for enthusiasts and power users of the Android operating system

Game Development

Q&A for professional and independent game developers

OnStartups

Q&A for entrepreneurs looking to start or run a new business

Cooking

Q&A for professional and amateur chefs

Electrical Engineering

Q&A for electronic hardware hacking enthusiasts

Photography

Q&A for professional, enthusiast and amateur photographers

Statistical Analysis

Q&A for statisticians, data analysts, data miners and data visualization experts

Drupal Answers

Q&A for Drupal developers and administrators

GIS

Q&A for cartographers, geographers and GIS professionals

User Experience

Q&A for user experience researchers and experts

Database Administrators

Q&A for database professionals who wish to improve their database skills and learn from others in the community

Physics

Q&A for active researchers, academics and students of physics

Personal Finance and Money

Q&A for people who want to be financially literate

Theoretical Computer Science

Q&A for theoretical computer scientists and researchers in related fields

Science Fiction and Fantasy

Q&A for science fiction and fantasy enthusiasts

Role-playing Games

Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games

Stack Apps

Q&A for apps, scripts, and development with the Stack Exchange API

Graphic Design

Q&A for professional graphic designers and non-designers trying to do their own graphic design

Jewish Life and Learning

Q&A for those who base their lives on Jewish law and tradition and anyone interested in learning more

Bicycles

Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles

Fitness and Nutrition

Q&A for physical fitness professionals, athletes, trainers, and those providing health-related needs

Board and Card Games

Q&A for people who like playing board games, designing board games or modifying the rules of existing board games

Homebrew

Q&A for dedicated home brewers and serious enthusiasts

Writers

Q&A for authors, editors, reviewers, professional writers, and aspiring writers

Code Golf

Q&A for programming puzzle enthusiasts and code golfers

Travel

Q&A for road warriors and seasoned travelers

Parenting

Q&A for parents, grandparents, nannies and others with a parenting role

Christianity

Q&A for committed Christians, experts in Christianity and those interested in learning more

Audio-Video Production

Q&A for engineers, producers, editors, and enthusiasts spanning the fields of audio, video, and media creation

Motor Vehicle Maintenance and Repair

Q&A for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles

Quantitative Finance

Q&A for finance professionals and academics

Software Quality Assurance and Testing

Q&A for software quality control experts, automation engineers, and software testers

Japanese Language and Usage

Q&A for students, teachers, and linguists wanting to discuss the finer points of the Japanese language

Personal Productivity

Q&A for people wanting to improve their personal productivity

German Language and Usage

Q&A for speakers of German wanting to discuss the finer points of the language and translation

Bitcoin

Q&A for Bitcoin crypto-currency enthusiasts

Cryptography

Q&A for software developers, mathematicians and others interested in cryptography

Philosophy

Q&A for those interested in logical reasoning

Astronomy

Q&A for expert and amateur astronomers and astrophysicists

French Language and Usage

Q&A for students, teachers, and linguists wanting to discuss the finer points of the French language

Signal Processing

Q&A for practitioners of the art and science of signal, image and video processing

Computational Science

Q&A for scientists using computers to solve scientific problems

Spanish Language and Usage

Q&A for students, teachers, and linguists wanting to discuss the finer points of the Spanish language

Literature

Q&A for literary enthusiasts and those passionate about the written word

Linguistics

Q&A for professional linguists and others with an interest in linguistic research and theory

Theoretical Physics

Q&A for scientific theorists and academic scholars interested in theoretical, research-level physics

LEGO® Answers

Q&A for LEGO® and building block enthusiasts

History

Q&A for historians and history buffs

Economics

Q&A for economists and graduate-level economics students

Firearms

Q&A for firearm experts and enthusiasts

Biology

Q&A for biology researchers, academics, and students

Chinese Language and Usage

Q&A for students, teachers, and linguists wanting to discuss the finer points of the Chinese language

Biblical Hermeneutics

Q&A for professors, theologians, and those interested in exegetical analysis of biblical texts

Healthcare IT

Q&A for healthcare IT professionals and solution providers

The Great Outdoors

Q&A for people who love outdoor activities, excursions, and outdoorsmanship

Cognitive Sciences

Q&A for practitioners and research professionals of the cognitive sciences

Poker

Q&A for serious players and enthusiasts of poker