On this page I have concentrated all links to the items, which can be downloaded from other pages of this site. Just to make it easy.
Intersection (the new version of the Cross Section script for Blender 2.4x)
Handle Panel (the new version of the old script for Blender 2.4x. The control panels are placed in the Properties editor, Scene tab)
Knife (this script was written by chromoly, not me. Like the Bevel add-on, it implements another missing feature of Blender 2.5)
Vertex Tools (a part of the popular Geom Tools Blender 2.4 script, ported to Blender 2.5)