QCAD – Open Source CAD System
qcad.org
qcad.org
A few things about QCAD:
1. The coolest feature is its CLI [1] and it runs beautifully on Linux/macOS/Windows. We use it for CAD to Tile map conversion and metadata extraction in our backend.
2. It looks like the rendering engine is single-threaded and does not support GPU acceleration. So watch out opening a complex CAD file.
3. There are some compatibility issues with AutoCAD files, especially Hatch. But it mostly works great.
[1]: https://www.qcad.org/en/products/qcad-command-line-tools
We have AutoCAD as well as DraftSight. I am happy to support this effort, particularly at such a low cost. The CAM and nesting part might actually find immediate use driving our laser cutting/engraving machine. I haven't installed it yet, will play with it tomorrow.
Any clone or alternative to AutoCAD eventually has to implement LISP support. DraftSight has it.
We have fairly extensive AutoLISP code that turns ACAD into quite a powerful tool for the right type of job. The codebase was developed for the design and construction of large technical installations where you have to manage thousands of cables of different types, calculate lengths, produce wiring lists, labels, etc.
You can easily see the use case from our competitior website: https://www.propelleraero.com
Civil3D is basically the industry standard and it is a GIS software.
We import many different GIS files into every drawing: property lines, jurisdicitons, roads, pipe networks, streams, topography etc.
You have to be a little careful when incorporating survey data (ground vs grid issues).
Then we draw onto various state plane projected coordinate systems. Creating pipe networks, road corridors, 3D grading and surfaces.
There's a bunch of analysis that comes out of that work as well. The beauty of Civil3d is that much of the analysis can be done IN the drawing. For obvious reasons that saves a lot of time.
People literally make whole careers just out of learning the ins and outs of civil3d.
One thing that I'm wondering about is a constraint-solving system - the documentation doesn't mention anything about sketch constraints. Usually a constraint system is pretty important in CAD work, so I wonder if there's plans to add one.
QCAD can't do constraints.
Can FreeCAD export the 2D drawings?
Yes, FreeCAD can export 2D. See https://wiki.freecadweb.org/Manual:Generating_2D_drawings
If you a looking constraint solver based 2D/3D CAD, take a look on SolveSpace.[0]
SolveSpace's constraint solver actually also (partially) ported for FreeCAD & Blender.[1]
Here are my SolveSpace showcases.[2]
[1] https://twitter.com/SolveSpace/status/1480033252157108232
And FreeCAD already has constraint solving in sketches. The tweet you've linked is about constraint solving in a non-default workbench (LinkStage3) that allows you to define constraints between separate parts when bringing them into a single assembly.
If you compare a list of features, there is probably no advantage.
People use solvespace because it is easier to use, has minimal UI which encourages working directly with the part. Its non-modal, meaning no workbenches, project files, or other overhead. As someone said, they actually enjoy using it.
It's good enough for many things, and the simplicity and fun make it the tool of choice for a small but growing community.
People use FreeCAD because it gets the job done, but people love Solvespace because... well because its Solvespace.
Exactly like Blender (which I use daily) it does every little thing in the most backwards, unintuitive way possible, but if you patiently learn its asinine way of doing things, it becomes very useful.
But I used it for the first time for a renovation of my apartment in 2004 and it isjust great that when I was discussing a renovation with a neighbor I could still use it with the old files.
I have even used it for design of complex footprints for electronic components before redoing them in KiCAD (electronic design software), because I found QCAD to be less clunky.
The biggest difference I see between these two is UI and the pace of development. LibreCAD is still being worked on, but the latest stable release was in 2016. Last patch for QCAD has been released four days ago.
Personally, I prefer QCAD to LibreCAD. Both are quirky to use, but QCAD is at least a little bit less quirky. If you are coming from AutoCAD, then both will be equally confusing.
[0] Maybe not literally, README file available in LibreCAD repo declares that "LibreCAD is a 2D CAD drawing tool based on the community edition of QCAD." On the other hand, Libre Arts article [1] calls it fork.
LibreCAD in same time has a better performance with big/complex drawings, than QCAD.
LibreCAD has not-great DWG support and is free. Last I remember reading about it, they were looking to get better DWG support via the LibreDWG library, but they needed to strip out and fully rewrite a bunch of old QCAD code to achieve that, due to licensing issues.
Their website is obnoxiously terrible and uninformative. Even when you manage to navigate to https://kittycad.io/about and its linked pages, it's not clear what KittyCAD actually is or will be, just that the founders intend to somehow add better scripting to CAD via a paid API.