Server Fault
Q&A for professional system and network administrators
Academia
Q&A for academics and those enrolled in higher education
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Meta Stack Overflow
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Mathematics
Q&A for people studying math at any level and professionals in related fields
Biology
Q&A for biology researchers, academics, and students
Web Applications
Q&A for power users of web applications
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Cross Validated
Q&A for statisticians, data analysts, data miners and data visualization experts
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
Reverse Engineering
Q&A for researchers and developers who explore the principles of a system through analysis of its structure, function, and operation