KAD is a KDE version of the 2D-CAD software QCad by ribbonsoft. It's a complete 2D-CAD system suitable for both beginning and advanced users. This KDE version has a user interface which is much closer to what people are used in KDE. The project is under GPL.
This is the main repository of KAD.
lists.tuxfamily.org/kad-general
All discussions about KAD, KDE aided design, both for users and developers