Programming
I program client and server side code in JavaScript, CoffeeScript, SQL, Java, and many other little languages using Vim or Eclipse. I master a flock of Linux VMs (without annoying remote desktops) via ssh, scp, git, screen, vi, awk, and small modular shell scripts.
Science
I regularly write scientific papers and create presentations for my PhD thesis, and all I need for that are LyX and Inkscape. To keep on track and stay focused, I out-source my brain, managing my knowledge and research ideas in Freeplane.
Stack Overflow
Q&A for professional and enthusiast programmers
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems.
Server Fault
Q&A for professional system and network administrators
Meta Stack Overflow
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Area 51
Stack Exchange Network staging zone, where users come together to build new Q&A sites