Physics
Q&A for active researchers, academics and students of physics
Mathematics
Q&A for people studying math at any level and professionals in related fields
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Stack Overflow
Q&A for professional and enthusiast programmers
Academia
Q&A for academics and those enrolled in higher education
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Mathematica
Q&A for users of Wolfram Mathematica
Signal Processing
Q&A for practitioners of the art and science of signal, image and video processing
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Network Engineering
Q&A for network engineers
Super User
Q&A for computer enthusiasts and power users
Amateur Radio
Q&A for amateur radio enthusiasts