ECam - Nice, fast and intuitive. A 2D Cad/Cam designed for simple machining operation
AutoCAD MEP - AutoCAD MEP software helps you draft, design, and document building systems.
FreeCAD - An open-source parametric 3D modeler
DataCAD - DataCAD is a computer-aided design and drafting software for 2D and 3D architectural design and drafting
PyCAM - PyCAM is a toolpath generator for 3-axis CNC machining.
AutoCAD Plant 3D - AutoCAD Plant 3D is a BIM software that lets you create, modify, and manage schematic piping and instrumentation diagrams.