I have been using LibreCAD, which is free 2D program. Quite powerful
LibreCAD is a fully comprehensive 2D CAD application that you can download and install for free. There is a large base of satisfied LibreCAD users worldwide, and it is available in more than 20 languages and for all major operating systems, including Microsoft Windows, Mac OS X and Linux (Debian, Ubuntu, Fedora, Mandriva, Suse ...). Here is a link to the homepage-
LibreCAD
You can download, install and distribute LibreCAD freely, with no fear of copyright infringement.
I have tried FreeCAD for 3d. Has a bit of a learning curve but works pretty good.
FreeCAD is a parametric 3D modeler. Parametric modeling allows you to easily modify your design by going back into your model history and changing its parameters. FreeCAD is open source (LGPL license) and completely modular, allowing for very advanced extension and customization.
FreeCAD is multiplatfom, and reads and writes many open file formats such as STEP, IGES, STL and others. Read more...
Who is FreeCAD for?
The home user/hobbyist. Got yourself a project you want to build, have built, or 3D printed? Model it in FreeCAD. No previous CAD experience required. Our community will help you get the hang of it quickly! Link to homepage
FreeCAD
Bill