Stack Overflow
Q&A for professional and enthusiast programmers
Mathematics
Q&A for people studying math at any level and professionals in related fields
Parenting
Q&A for parents, grandparents, nannies and others with a parenting role
Cross Validated
Q&A for statisticians, data analysts, data miners and data visualization experts
Programming Puzzles & Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Physics
Q&A for active researchers, academics and students of physics
Meta Stack Overflow
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems.
Programmers
Q&A for professional programmers interested in conceptual questions about software development
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Cognitive Sciences
Q&A for practitioners, researchers, and students in cognitive science, psychology, neuroscience, and psychiatry
Area 51
Stack Exchange Network staging zone, where users come together to build new Q&A sites
