C/C++ programmer, PostgreSQL programmer/DBA, System and Network administrator. There are a few things that cannot really be done. And all of them are well known and documented.
Q&A for professional and enthusiast programmers
Q&A for Ubuntu users and developers
Q&A for computer enthusiasts and power users
Q&A for power users of web applications
Q&A for database professionals who wish to improve their database skills and learn from others in the community