Looking for freeware or opensource CAD that can read and edit .dwg

Question

We have an engineer who needs CAD software which can read and edit .dwg files (preferably that runs on Windows but I could probably argue for a *nix box if needed). Before buying a commercial license I'd like to see, what if any, freeware or opensource CAD software exists. I've read through this post but the software here all specifies a license for personal use only. Everything I have found up to this point is a .dwg viewer only, is licensed for non-commercial purposes, or is paid software (with the possible exception of FelixCAD which I'm still looking into).

There are some really cool CAD packages such as BRL-CAD or Archimedes but these don't have the capability to work with .dwg files. My question then is, am I right that there is no freeware (with a commercial license) or opensource CAD software which can work with .dwg files? Or am I wrong and there is just such a package out there?

Answer 1

Free CAD products that support dwg:

DoubleCAD XT

DoubleCAD XT™ is an AutoCAD LT work-alike. But free.

A9CAD

A9CAD is a general purpose two-dimensional CAD program. It supports industry standard DWG & DXF drawing formats.

HYCAD

HYCAD is a useful and general purpose CAD program, green and small but powerful.
HYCAD can export multiple format files, such as dwg dxf eps bmp jpg png etc. it is easy to learn and much like AutoCAD.

Answer 2

The only thing I could find on sourceforge when searching on the keyword DWG that mentioned anything about writing DWG files was OpenDWG. However, OpenDWG has not posted any files.

On the bright side, there is some code in their SVN repository. The mention that you can check out their repository as follows:

svn co https://opendwg.svn.sourceforge.net/svnroot/opendwg opendwg

Other than that, I agree with ldigas' answer in that DWG is a proprietary format.

Answer 3

I don't think you'll so easily find an open source one, which handles .dwg. For starters, .dwg is not open source (there have been some initiatives to make part of it public, but it never lived on fully).

As far as CAD goes on *nix boxes, in general, it was never spread as on Win ones, starting from software, up to drivers for specific used graphic cards, and so on ...

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However, what you could do, if you're interested in writing a interface to a already existing format, is check out openNURBS. It is a Rhino community project (that has already taken some development), and if I understand correctly they provide an acess to Rhino's format (a NURBS modeling application, which is very respected in its own domains of application).

But this is just a sidenote.

Answer 4

There is a product called Free DWG Viewer from Informative Graphics.

http://infograph.com/products/viewers.htm - It is the product on the far right.

Was the question edited? I find it hard to believe that I completely misread the question.

Answer 5

http://www.mscad.com.br/

PROS - light and portable
CONTRAS - in Portuguese only and some ads