ratpoison: (screen for X) tilling windows manager . No borders, no title bar, all the applications are in "fullscreen"
tmux: terminal multiplexer (`tabs' and splits). Successor of screen.
vim; a text editor
git: version control
Ubuntu 13.04 with Gnome 3.8 on my personal laptop. I love it, I don't care about the criticism it gets.
At work, I just use Debian with KDE and I manage a RHEL6 server. We run mostly red hat for our servers.
I use Crunchbang and have Qt Creator, Vim, Emacs, Geany, Netbeans, Eclipse, Code::Blocks, KDEvelop, nano, and a ton of other apps as I do more than program.
Ubuntu on a laptop was too much of a CPU hog, which is why I use Crunchbang now. Ubuntu, at idle on my laptop was about 20-30%, Crunchbang is 1-2% idle.