Mathematician and programmer interested in helping others.
Mathematics
Q&A for people studying math at any level and professionals in related fields
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
Super User
Q&A for computer enthusiasts and power users
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Quantitative Finance
Q&A for finance professionals and academics
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Server Fault
Q&A for system and network administrators
Computer Science
Q&A for students, researchers and practitioners of computer science
Stack Overflow на русском
Вопросы и ответы для программистов
Computational Science
Q&A for scientists using computers to solve scientific problems
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
History
Q&A for historians and history buffs
Ask Ubuntu
Q&A for Ubuntu users and developers
Cross Validated
Q&A for people interested in statistics, machine learning, data analysis, data mining, and data visualization
Code Review
Q&A for peer programmer code reviews
Mathematica
Q&A for users of Wolfram Mathematica
Area 51
Q&A for proposing new sites in the Stack Exchange network