Stack Overflow
Q&A for professional and enthusiast programmers
Mi Yodeya
Q&A for those who base their lives on Jewish law and tradition and anyone interested in learning more
Quantum Computing
Q&A for engineers, scientists, programmers, and computing professionals interested in quantum computing
Data Science
Q&A for Data science professionals, Machine Learning specialists, and those interested in learning more about the field
Writing
Q&A for the craft of professional writing, including fiction, non-fiction, technical, scholarly, and commercial writing
Physics
Q&A for active researchers, academics and students of physics
Super User
Q&A for computer enthusiasts and power users
Skeptics
Q&A for scientific skepticism
Lifehacks
Q&A for people looking to bypass life's everyday problems with simple tricks
Artificial Intelligence
Q&A for people interested in conceptual questions about life and challenges in a world where "cognitive" functions can be mimicked in purely digital environment
Computer Science
Q&A for students, researchers and practitioners of computer science
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Philosophy
Q&A for those interested in the study of the fundamental nature of knowledge, reality, and existence
Web Applications
Q&A for power users of web applications
Academia
Q&A for academics and those enrolled in higher education
Mathematics
Q&A for people studying math at any level and professionals in related fields
Server Fault
Q&A for system and network administrators
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems