Well, it should be mentioned here - OpenSCAD is free software, it is lightweight and flexible tool. QCAD might be your choice too (it is open source and powerful software, but I am not sure if it is free). OnShape is a cloud-based CAD solution. But personally I am still a SolidWorks fan and I haven't found any software that can compete with it yet (because of its compatibility with so many 3D scanning and modeling tools like Artec Studio etc). It's only possible to run with a virtual machine.