Innovation 3D Modeler
Thanks to Michael Kurth who sent along a link to Innovation3D, an open source 3D modeler for Linux with many features. Here's a kerchunk of information from their site:
Innovation3D is a well-featured, open source, 3-dimensional modelling program developed for Linux. Work on I3D began when I was frustrated from the lack of tools available for Linux 3D game development. While excellent libraries exist (such as Mesa and PLIB), the lack of content creation tools was evident. The Gimp only fills half of the role for 3D game development. Several modelling programs exist, but they lacked any real flexibility, are orientated towards raytracing or were not free/opensource. So work began on I3D.
I3D utilizes a variety of techniques for modelling. You can create splines, meshes, and surfaces. Sweep/revolve a spline into a triangle mesh, or a Nurbs surface. Modify object properties with the mouse or with the object inspector. Texture map objects for added detail, and fine tune the mapping coordinates with the UVEditor. Create keyframe animations, using IK and skeletal deformation. You can even animate colors and UV coords. "