Stack Overflow
Q&A for professional and enthusiast programmers
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Pets
Q&A for pet owners, caretakers, breeders, veterinarians, and trainers
Personal Finance & Money
Q&A for people who want to be financially literate
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Retrocomputing
Q&A for vintage-computer hobbyists interested in restoring, preserving, and using the classic computer and gaming systems of yesteryear
Vi and Vim
Q&A for people using the vi and Vim families of text editors
Super User
Q&A for computer enthusiasts and power users
Photography
Q&A for professional, enthusiast and amateur photographers
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Server Fault
Q&A for system and network administrators
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Information Security
Q&A for information security professionals