Boundaries of an Open Source clone of proprietary software

Question

Let's assume we have a program A that is shareware and closed source. Albeit it being the most popular of its kind, it suffers from a lack of updates and some annoying, yet long-outstanding bugs.

This prompts developer M to start an open source clone B of said program A. To make switching from A to B as easy as possible, M is going to make B's program dialogs (menus, settings...) resemble A's as much as possible.

The question that arises now is whether this is a legal undertaking or not. M of course won't copy any code or another resources from A, but he is going to model the GUI to look and feel very similar (at least to a certain point, from where on the project is going to evolve on its own path).

I searched the net for examples, but didn't find anything of substance. Any ideas? Thanks!

Answer 1

I think the EULA of program A is the only real source to resolve this. Typically these license agreements say things about not reverse engineering and decompiling.

more informally, I guess it depends on the extent to which program A has a unique and distinct way of making menus and dialogs.

If it would rely on the standard widgets and look and feel offered by the operating system, and common conventions to organize menus, it think it would be ok...i mean, there's only so many ways to set up a File... menu, no?

If on the other hand program A has a set of unique widgets and a revolutinary way to organize the gui, well, that's a different ballgame.

If you want to know for sure, I suggest to seek legal advice. I don't think stackoverflow is the best place to resolve this.

Answer 2

I'm a shareware developer and was a longtime member of ASP (Association of Shareware Professionals). This issue came up many times in the newsgroups almost always about chinese programmers who made an exactly clone and offered it as shareware too. The only way to stop them is if they use icon or font artwork.

There was a Lotus <-> visicalc lawsuit (also mentioned in http://en.wikipedia.org/wiki/Lotus_1-2-3) which made clear that this is a common mode of operation. And the wiki articles is not 100% correct, it is not only covering the menu structure but also dialogs and the whole GUI including keystroke combinations.