Area 51
Stack Exchange Network staging zone, where users come together to build new Q&A sites
Meta Stack Overflow
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Server Fault
Q&A for professional system and network administrators
Programmers
Q&A for professional programmers interested in conceptual questions about software development
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Stack Apps
Q&A for apps, scripts, and development with the Stack Exchange API
WordPress Answers
Q&A for WordPress developers and administrators
User Experience
Q&A for user experience researchers and experts
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Ask Different
Q&A for power users of Apple hardware and software
Game Development
Q&A for professional and independent game developers
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Photography
Q&A for professional, enthusiast and amateur photographers
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems.
Windows Phone
Q&A for enthusiasts and power users of Windows Phone OS
Audio-Video Production
Q&A for engineers, producers, editors, and enthusiasts spanning the fields of audio, video, and media creation
Personal Finance & Money
Q&A for people who want to be financially literate
Answers OnStartups
Q&A for entrepreneurs looking to start or run a new business
Writers
Q&A for authors, editors, reviewers, professional writers, and aspiring writers
Parenting
Q&A for parents, grandparents, nannies and others with a parenting role