Apparently, this user prefers to keep an air of mystery about them.
Stack Overflow
Q&A for professional and enthusiast programmers
Travel
Q&A for road warriors and seasoned travelers
The Workplace
Q&A for members of the workforce navigating the professional setting
Super User
Q&A for computer enthusiasts and power users
Personal Finance & Money
Q&A for people who want to be financially literate
Cryptography
Q&A for software developers, mathematicians and others interested in cryptography
Board & Card Games
Q&A for people who like playing board games, designing board games or modifying the rules of existing board games
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Information Security
Q&A for information security professionals
The Great Outdoors
Q&A for people who love being outdoors enjoying nature and wilderness, and learning about the required skills and equipment
Software Engineering
Q&A for professionals, academics, and students working within the systems development life cycle
Motor Vehicle Maintenance & Repair
Q&A for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles
Open Source
Q&A for people organizing, marketing or licensing open source development projects
Earth Science
Q&A for those interested in the geology, meteorology, oceanography, and environmental sciences
Physical Fitness
Q&A for physical fitness professionals, athletes, trainers, and those providing health-related needs
Law
Q&A for legal professionals, students, and others with experience or interest in law
Politics
Q&A for people interested in governments, policies, and political processes
Home Improvement
Q&A for contractors and serious DIYers
Geographic Information Systems
Q&A for cartographers, geographers and GIS professionals
Server Fault
Q&A for system and network administrators
Open Data
Q&A for developers and researchers interested in open data
Biology
Q&A for biology researchers, academics, and students
Arqade
Q&A for passionate videogamers on all platforms
Space Exploration
Q&A for spacecraft operators, scientists, engineers, and enthusiasts
Ask Ubuntu
Q&A for Ubuntu users and developers
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Graphic Design
Q&A for Graphic Design professionals, students, and enthusiasts
Movies & TV
Q&A for movie and TV enthusiasts
Seasoned Advice
Q&A for professional and amateur chefs
Physics
Q&A for active researchers, academics and students of physics
Web Applications
Q&A for power users of web applications
Raspberry Pi
Q&A for users and developers of hardware and software for Raspberry Pi
Drones and Model Aircraft
Q&A for experienced flyers, pilots, and builders of drones and model aircraft
Mathematics
Q&A for people studying math at any level and professionals in related fields
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Worldbuilding
Q&A for writers/artists using science, geography and culture to construct imaginary worlds and settings
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
Bicycles
Q&A for people who build and repair bicycles, people who train cycling, or commute on bicycles
Pets
Q&A for pet owners, caretakers, breeders, veterinarians, and trainers
Blender
Q&A for people who use Blender to create 3D graphics, animations, or games
Engineering
Q&A for professionals and students of engineering
Hardware Recommendations
Q&A for people seeking specific hardware recommendations
Code Review
Q&A for peer programmer code reviews
Magento
Q&A for users of the Magento e-Commerce platform
WordPress Development
Q&A for WordPress developers and administrators
Ethereum
Q&A for users of Ethereum, the decentralized application platform and smart contract enabled blockchain
Bitcoin
Q&A for Bitcoin users, developers, and enthusiasts
Video Production
Q&A for engineers, producers, editors and enthusiasts spanning the fields of video and media creation
Computer Science
Q&A for students, researchers and practitioners of computer science
Mathematica
Q&A for users of Wolfram Mathematica
User Experience
Q&A for user experience researchers and experts
Software Recommendations
Q&A for people seeking specific software recommendations
Music: Practice & Theory
Q&A for musicians, students, and enthusiasts
Ask Different
Q&A for power users of Apple hardware and software
History
Q&A for historians and history buffs
Photography
Q&A for professional, enthusiast and amateur photographers
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
Literature
Q&A for scholars and enthusiasts of literature
Code Golf
Q&A for programming puzzle enthusiasts and code golfers
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Academia
Q&A for academics and those enrolled in higher education
Interpersonal Skills
Q&A for people looking to improve their interpersonal communication skills
Area 51
Q&A for proposing new sites in the Stack Exchange network
Christianity
Q&A for committed Christians, experts in Christianity and those interested in learning more
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community