KLandscape - A program that allows you to create 3D rendered landscapes through an easy to use User Interface. - http://www.witchspace.com/landscape.html
KPovModeler - A modeler for povray scenes for KDE. Provides News about the application, screenshots, downloads, installation and contact information. - http://www.kpovmodeler.org/
K3Studio - A universal workbench for 2d/3d modeling, visualization and simulation. - http://k3studio.sourceforge.net/
Innovation3D - A 3-dimensional modeling program developed using the Qt Library. - http://innovation3d.sourceforge.net/