ServerSide
Serverside scripting is what makes most of our sites tick. We can work in two server side languages: PHP and ASP.
PHP in collaboration with a database can be very powerfull.
For example, this site is driven by PHP and mySQL. We do not edit files and upload to the server, but instead we use a login-feature and edit all texts through forms. This also gives us the ability to use BLOG software, gallery functions, forums, shops, etc.
We do most of our stuff in-house, but we do occationally use other software. Most commonly used is phpBB which is a very advanced and good forum-application that is easy to customize to different designs and layouts.