Stack Overflow
Q&A for professional and enthusiast programmers
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Blender
Q&A for people who use Blender to create 3D graphics, animations, or games
Chemistry
Q&A for scientists, academics, teachers, and students in the field of chemistry
Super User
Q&A for computer enthusiasts and power users
Role-playing Games
Q&A for gamemasters and players of tabletop, paper-and-pencil role-playing games
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Arduino
Q&A for developers of open-source hardware and software that is compatible with Arduino
Mathematics
Q&A for people studying math at any level and professionals in related fields
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Information Security
Q&A for information security professionals
Arqade
Q&A for passionate videogamers on all platforms
Politics
Q&A for people interested in governments, policies, and political processes
Hardware Recommendations
Q&A for people seeking specific hardware recommendations