Good free program for viewing (and maybe modifying) DWG files?

In My Humble Opinion
1

Anyone use such program? I need to be steered in the right direction. I don’t want to install a bunch of free programs only to try them out and have them be crappy or loaded with spyware or such.
I got some CAD drawings on a disk that I mostly want to just view, but there may come a time when I’ll need to make some changes too.

Thanks

2

Autodesk Design Review is free. I’ve not used it myself, so can’t comment on its utility, but it’s from the makers of AutoCAD.

3

Installing as I type Quartz, thanks for the link.