Stack Overflow
Q&A for professional and enthusiast programmers
Super User
Q&A for computer enthusiasts and power users
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Web Applications
Q&A for power users of web applications
Personal Finance & Money
Q&A for people who want to be financially literate
Area 51
Q&A for proposing new sites in the Stack Exchange network
Arqade
Q&A for passionate videogamers on all platforms
Physical Fitness
Q&A for physical fitness professionals, athletes, trainers, and those providing health-related needs
Stack Apps
Q&A for apps, scripts, and development with the Stack Exchange API
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Mathematics
Q&A for people studying math at any level and professionals in related fields
Internet of Things
Q&A for builders and users of networked sensors and control devices in the contexts of smart homes, industry automation, or environmental sensors
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
Quantitative Finance
Q&A for finance professionals and academics
Information Security
Q&A for information security professionals
Home Improvement
Q&A for contractors and serious DIYers
Project Management
Q&A for project managers
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Medical Sciences
Q&A for professionals in medical and allied health fields, students of those professions, related academics, and others with a sound understanding of medicine and healthcare-related sciences
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Server Fault
Q&A for system and network administrators