Stack Overflow
Q&A for professional and enthusiast programmers
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Open Source
Q&A for people organizing, marketing or licensing open source development projects
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Super User
Q&A for computer enthusiasts and power users
Sound Design
Q&A for sound engineers, producers, editors, and enthusiasts
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Software Recommendations
Q&A for people seeking specific software recommendations
Hardware Recommendations
Q&A for people seeking specific hardware recommendations
Computer Graphics
Q&A for computer graphics researchers and programmers
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
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