I'm a professional Java developer, occasionally studying for the Java programmer's certification exam, and in the meantime refreshing my knowledge of C, C++, UNIX programming, Perl, Python, and more. My operating system of choice is Linux, database is MySQL, and language varies--sometimes it's Java, sometimes it's Python, sometimes it's C++. I like Java's threading model because it's so easy to program once you get used to it. I like C++ because you can compile the program down into fast code. I like Python because it's just the perfect language for the quick, but maintainable, programs you need to develop.
My current at home projects include a graphical, multi-player Java MUD I'm calling 'sso' (Swords and Sorcery Online), a database and web application written in Python to help my wife keep track of her model horses, and studying C and C++ so I can eventually convert sso into a compiled language. I'm note expecting the server to be able to handle a lot of connections, but I might be mistaken--I write fairly efficient Java. Additionally, I'm finishing up a project I started in college, Dragonia, a MOO based in a fantasy land dominated by dragons.
-- Chris Jones