It is an open source parametric 3D CAD software based on Open Cascade, like FreeCAD. They've been around for some time but they're not well known. It was started much later than FreeCAD so it's not as further along in its development.
Its main problem for me is it's based on Microsoft's .NET framework, so it is a Windows-only application.
The last time I tried it on Windows the installer wouldn't even work, but that was during the Alpha stage. It's reached Beta status and there are some positive reviews on Sourceforge so I guess the software can be installed and ran now.
