I have been wondering how to make a tab menu for one of my site's.

I have found a good example but don't know how to recreate something like this. Is there an easy to use php/javascript for this?

Example:
http://www.sculp-consult.nl/

That particular menu can be done with CSS only, or using javascript.

Here is one method: http://www.htmldog.com/articles/tabs/
I think you can find a few here too: http://www.cssplay.co.uk/menus/