As of June 2013 I work for Stack Exchange!
I've been a big fan of Stack Exchange since the start. Literally. I was listening to Joel's podcast when he and Mark would talk about this secret project idea they had, I was excided when they finally said what it was, I was in the secret beta, and I've been a big fan since it went live!
The new hotness: Puppet, Linux (CentOS), Mac OS X, Python.
Old and broken (my knowledge is atrophying due to lack of use): Perl, Solaris, FreeBSD.
System administrator, network engineer, time management guru, speaker, author of 3 books, and generally silly person. I wrote "Time Management for System Administrators" from O'Reilly. I co-wrote "The Practice of System and Network Administration".
I work at StackExchange, owner of ServerFault and StackOverflow, but I do not speak for them.
Q&A for professional system and network administrators
Q&A for scientific skepticism
Q&A for professional and enthusiast programmers
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems.
Q&A for project managers
Q&A for people who want to be financially literate
Q&A for aircraft pilots, mechanics, and enthusiasts
Q&A for power users of web applications
Q&A for peer programmer code reviews
Q&A for network engineers
Q&A for professional programmers interested in conceptual questions about software development
Q&A for linguists, etymologists, and serious English language enthusiasts
Q&A for user experience researchers and experts
Q&A for power users of Apple hardware and software
Q&A for people studying math at any level and professionals in related fields
Q&A for active researchers, academics and students of physics
Q&A for apps, scripts, and development with the Stack Exchange API
Q&A for Ubuntu users and developers
Q&A for professional mathematicians
Q&A for academics and those enrolled in higher education
Q&A for Information security professionals
Q&A for contractors and serious DIYers
Q&A for members of the workforce navigating the professional setting
Q&A for computer enthusiasts and power users
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Q&A for parents, grandparents, nannies and others with a parenting role
Q&A for people wanting to improve their personal productivity
Q&A for people interested in improving and participating in the patent system
Q&A for authors, editors, reviewers, professional writers, and aspiring writers
Q&A for folks dedicated to a lifestyle that can be maintained indefinitely without depleting available resources
Q&A for people interested in governments, policies, and political processes
Q&A for pet owners, caretakers, breeders, veterinarians, and trainers
Q&A for Graphic Design professionals, students, and enthusiasts