# Why open-source CAD rarely looks like the commercial packages

- Link: https://opensourcecad.nl/en/why-open-source-cad-rarely-looks-like-the-commercial-packages/
- Published: 2026-10-24T01:47:10+02:00
- Author: Marijn van den Heuvel \+ AI

_This is the English reading version of the Dutch news item [Waarom open-source CAD zelden op de commerciële pakketten lijkt](https://opensourcecad.nl/vibecoded-apps/waarom-open-source-cad-zelden-op-de-commerciele-pakketten-lijkt/)._

Open-source software used to be made by the developer who needed it himself. What
is being added lately is made out of frustration: someone wants what a commercial
package does, but then free of charge. That explains why those new programs do look
like the packages everyone knows, and the older generation does not.

## It was never forbidden

For a long time I thought you were not allowed to make a free clone of Adobe. That
is not true. In 2012 the Court of Justice ruled in the case of SAS Institute against
World Programming that the functionality of a program, the programming language 
and the file formats are not covered by copyright, and that you may observe, study
and test a program to understand the ideas behind it.

What is protected: the code as it is written, the name of the product, and the look
of it as far as it creates confusion about who made it. Individual ideas can fall
under a patent. So you may copy a program that does the same thing, as long as you
do not take over the code and do not pretend you are the original. The law was never
the problem.

## The ribbon as an example

Take the ribbon, the bar with tabs that Microsoft introduced in 2007 and that is
now in most CAD programs. In FreeCAD it is still not there by default, while it 
has been possible for years: there are addons that prove it (FreeCAD-Ribbon, ModernUI,
NeoRibbon), LibreOffice has had a ribbon since 5.3, and according to the forum Microsoft’s
patent on the ribbon has lapsed. It was not the toolkit either: those addons run
on FreeCAD’s own building blocks.

There is a counterargument, but it does not hold. A piece by Ondsel says it is not
about the ribbon: whoever complains about it is really complaining about consistency
and discoverability. Don Norman says in _The Design of Everyday Things_: “Violate
conventions and you are marked as an outsider. A rude outsider, at that.” To him
conventions are cultural constraints: you learn them from your surroundings, and
so also from the programs you already use. A design should therefore be what the
user expects, not what is logical. The ribbon is such an expectation, and consistency
and discoverability come on top of it.

What holds it back is in the discussion itself: it is a big rebuild, it meets resistance,
and a maintainer wrote in 2024 that it will not happen soon. That is not a technical
problem but a choice about where the development is heading.

## Who is actually asking for it?

A developer who does not sell his software has no customers in the sense of buyers.
He has donors, and they are customers just as much: they pay, so they may expect
to be listened to. It is just that they are often not seen that way. That is the
core of my argument: projects that live on donations throw away their own chances
by not treating their donors as customers.

## What is changing now

The new wave starts elsewhere. Take SolidCraft: open source, parametric, in Rust,
with a ribbon at the top with the tabs Solid, Surface, Mesh, Sheet Metal, Plastic
and Utilities, the model tree on the left and the timeline at the bottom. That is
the layout of Fusion 360, down to the tab names. Where the older generation started
with what was technically interesting, this one starts with the program people already
know, but then free of charge.

**My verdict:** as a UI developer I have always said that FreeCAD is not a market
leader and therefore should not innovate in the interface. Users expect what they
know from the leaders, even if that is not the best design. That is why the themes
of FreeCAD are now dull grey and white tints instead of purple: that is what a professional
program looks like, and I added that, I did not invent it. As long as developers
do not see their donors as customers, and do not accept that they should not develop
the interface themselves, those old open-source programs will keep looking strange,
and that plays straight into the hands of the vibecoded programs that do get this
right.

I read the explanation about copyright on functionality at [Licenseware](https://licenseware.io/ai-rebuilt-adobe-microsoft-apps-open-source/);
the case SAS Institute against World Programming is from the Court of Justice, and
the directive is 2009/24/EC. The Norman quote is from The Design of Everyday Things,
revised edition, in the chapter about conventions. About the ribbon in FreeCAD: 
the [thread on the developers forum](https://devtalk.freecad.org/t/draft-for-ribbon-modern-ui/6344),
the [discussion on GitHub](https://github.com/FreeCAD/FreeCAD/discussions/13775),
the [addons on the wiki](https://wiki.freecad.org/External_workbenches) and the 
piece by [Ondsel](https://www.ondsel.com/blog/freecad-breaking-open-source-ux-curse/).
SolidCraft is at [solidcraft.io](https://solidcraft.io/), the layout can be seen
on the [project’s example page](https://solidcraft.io/showcase/pi-enclosure/).