Big fan of Linux (and in turn FOSS projects) so I'm a KDE + Ubuntu (moving to Debian when I can get all of my PPAs in easily) kind of guy. I use Krita/Karbon for slicing up PSDs and making quick vector images, Pencil for wireframes and light mockups and mainly Konsole, Vim and tmux for all of my webdev works (as well as Chrome and Firefox).
As long as you conform to standards, webdev is easy.
As long as you conform to standards, webdev is easy.