USER FORUM
(you are viewing a thread; or go back to list of threads)
License infringement? (by Poon)
I stumbled across a 2D CAD for packaging.
http://www.rulessoftware.com/
The appearance is exactly the same as solvespace, and it uses slvs extension file.
If I recalled correctly, GNU GPLv3 requires disclosure of source as well as being released under same license. I believe this rule software is sold commercially. Is this considered a license infringement?
http://www.rulessoftware.com/
The appearance is exactly the same as solvespace, and it uses slvs extension file.
If I recalled correctly, GNU GPLv3 requires disclosure of source as well as being released under same license. I believe this rule software is sold commercially. Is this considered a license infringement?
(no subject) (by Eric Buijs)
The interface of Sample Maker 2D looks indeed almost identical to Solvespace. And you're correct about the GNU GPLv3 license and the possible infringement. In theory it could of course also be that Solvespace is infringing the Rules Software license although the slvs extension makes that hard to believe.
(no subject) (by Mike O)
May have been a scam by said Michael Collins. He took the Solvespace, customized it for a particular industry, and then...
AlphaCorr acquired Rules Software in 2008.
http://www.alphacorr.com/about/
AlphaCorr acquired Rules Software in 2008.
http://www.alphacorr.com/about/
SketchFlat not SolveSpace (by Mike C)
The 2D version of SketchFlat existed before SolveSpace. It was "Unrestricted" code, with no GNU GPLv3 license at that time. SketchFlat was the predecessor to SolveSpace. They both use a constraint solver style that traces back to Ivan Sutherland’s MIT Sketchpad from 1962. Alphacorr uses Ashlar-Vellum CAD, which was also based on Sutherland’s solver. It all originates from 1962. Sketchpad? SketchFlat? >> SolveSpace.
(no subject) (by ruevs)
That's an interesting way to draw attention to an old story. https://www.samplemaker.com/RulesSoftware.com/
The current https://samplemaker.com/ is so obviously basd on SolveSpace that it certainly violates the GPL by not being open source.
Anyway...
The current https://samplemaker.com/ is so obviously basd on SolveSpace that it certainly violates the GPL by not being open source.
Anyway...
(no subject) (by ruevs)
Ans SketchFlat is GPL as well https://cq.cx/sketchflat.pl
Unrestricted (by Mike C)
SketchFlat wasn’t GPL-licensed at the time, which is exactly when the codebase split occurred. Naturally the two projects look similar—they both originated from the same source. The SketchFlat solver has always worked very well for packaging applications. I even discussed this directly with Jonathan Westhues over email back then.
https://youtu.be/v6MCQcksB0g
https://youtu.be/v6MCQcksB0g
(no subject) (by Jonathan Westhues)
Thanks to everyone for bringing this to my attention, and sorry I missed it the first time. (I guess I enjoy writing software more than I enjoy enforcing software licenses.)
I've attached my complete email excerpted in the video linked above. Everyone is indeed free to use models created in SolveSpace for any purpose, commercial or noncommercial. The software itself is licensed under the GPLv3 though. So if a binary derivative work is distributed, then the source must be distributed under the GPL. Any IP lawyer can confirm this.
SolveSpace was initially published as commercial software with a free trial, then as unrestricted freeware (without source available), and finally as free software (with source) under the GPLv3. I haven't yet investigated deeply, but the tool linked above sure looks like it's derived from SolveSpace. Due to the technical difficulty of modifying binary files, it is most likely that any derivative was prepared from the GPL-licensed source. (This doesn't mean a derivative of the binary would be compliant, just that that such a case seems too unlikely to spend time discussing now.)
Open-source license noncompliance is usually resolved amicably, and I hope that can happen here to any extent necessary. The requirement would simply be to publish any code derived from GPL code like SolveSpace under that same license. Nothing would prevent the developer from continuing to sell the compiled tool, support services, libraries of models, related tools not containing GPL code in separate executables, etc.
Litigation has confirmed the validity of the GPL in American, European, and other courts, as described for example at
https://sfconservancy.org/copyleft-compliance/past-lawsuits.html
I believe noncompliance is almost always resolved before that point, though. I'll start a private thread with Paul (the current maintainer) and ruevs, and we can plan our next steps.
SketchFlat was initially published as unrestricted freeware (without source available), then under the GPLv3. So a closed-source derivative of SketchFlat would be likewise noncompliant.
I've attached my complete email excerpted in the video linked above. Everyone is indeed free to use models created in SolveSpace for any purpose, commercial or noncommercial. The software itself is licensed under the GPLv3 though. So if a binary derivative work is distributed, then the source must be distributed under the GPL. Any IP lawyer can confirm this.
SolveSpace was initially published as commercial software with a free trial, then as unrestricted freeware (without source available), and finally as free software (with source) under the GPLv3. I haven't yet investigated deeply, but the tool linked above sure looks like it's derived from SolveSpace. Due to the technical difficulty of modifying binary files, it is most likely that any derivative was prepared from the GPL-licensed source. (This doesn't mean a derivative of the binary would be compliant, just that that such a case seems too unlikely to spend time discussing now.)
Open-source license noncompliance is usually resolved amicably, and I hope that can happen here to any extent necessary. The requirement would simply be to publish any code derived from GPL code like SolveSpace under that same license. Nothing would prevent the developer from continuing to sell the compiled tool, support services, libraries of models, related tools not containing GPL code in separate executables, etc.
Litigation has confirmed the validity of the GPL in American, European, and other courts, as described for example at
https://sfconservancy.org/copyleft-compliance/past-lawsuits.html
I believe noncompliance is almost always resolved before that point, though. I'll start a private thread with Paul (the current maintainer) and ruevs, and we can plan our next steps.
SketchFlat was initially published as unrestricted freeware (without source available), then under the GPLv3. So a closed-source derivative of SketchFlat would be likewise noncompliant.
Thank you Jonathan Westhues (by Mike C)
I’ve always appreciated your kindness and generosity. When I began adapting my Box library to use your point resolver, the only thing I saw was the copyright notice with your name. I originally found your code while researching Ivan Sutherland and point‑resolving techniques, and I remembered the discussions we had back in 2016. Because of that, I genuinely believed I had permission to use your code.
With today’s AI tools, I can rewrite the constraint solver myself if that helps resolve any concerns. A friend recently found this thread and brought it to my attention, and this was the first time I realized there was an issue.
Please understand that I never acted with any malicious intent. I’ve had my own intellectual property taken throughout my life, so I would never knowingly misuse someone else’s work. At the same time, I don’t want to be publicly accused of stealing or doing anything with malice, especially since I truly believed I had permission. I also have no problem sharing the source code openly, selling only my Box library, or switching entirely to a rewritten version—whatever works best for you.
With today’s AI tools, I can rewrite the constraint solver myself if that helps resolve any concerns. A friend recently found this thread and brought it to my attention, and this was the first time I realized there was an issue.
Please understand that I never acted with any malicious intent. I’ve had my own intellectual property taken throughout my life, so I would never knowingly misuse someone else’s work. At the same time, I don’t want to be publicly accused of stealing or doing anything with malice, especially since I truly believed I had permission. I also have no problem sharing the source code openly, selling only my Box library, or switching entirely to a rewritten version—whatever works best for you.
Full disclosure (by Mike C)
Here is a link to the second version of SampleMakerV2 source—this was also widely distributed and is the only version that was built on SolveSpace, It was created by Ukrainian programmers they added named variables. I’ve also attached the full email. I have a New 100% Ai Web version CAD and will stop using anything related to SloveSpace or SketchFlat.
https://drive.google.com/file/...eKGduGZBII/view?usp=drive_link
https://drive.google.com/file/...eKGduGZBII/view?usp=drive_link
(no subject) (by ruevs)
Attached is a PDF with the now deleted https://www.samplemaker.com/RulesSoftware.com/ URL that I posted "yesterday" (2026-01-15).
@MikeC The Google drive URL that you posted above is not accessible (at least not publicly).
@MikeC The Google drive URL that you posted above is not accessible (at least not publicly).
Try link again (by Mike C)
@ruevs
I’m in the process of removing all references to SolveSpace and SketchFlat, along with all related code. SolveSpace really should support Name Variables, since many of its users design packaging and would benefit from that functionality.
For clarity: SampleMaker has never been sold commercially — only the Box Library. The source code was always available to anyone who asked under GPLv3, and there may have been a download link for the source about ten years ago. The Windows (.exe) and Mac versions were always free to download.
I’m glad this thread was found now, because I was just about to start a subscription service to the library. It also gives me a push to get the New Ai web 2D CAD version finished. Like Jonathan, I get more enjoyment from creating parametric designs — it’s a challenge, almost like solving a puzzle.
I’m in the process of removing all references to SolveSpace and SketchFlat, along with all related code. SolveSpace really should support Name Variables, since many of its users design packaging and would benefit from that functionality.
For clarity: SampleMaker has never been sold commercially — only the Box Library. The source code was always available to anyone who asked under GPLv3, and there may have been a download link for the source about ten years ago. The Windows (.exe) and Mac versions were always free to download.
I’m glad this thread was found now, because I was just about to start a subscription service to the library. It also gives me a push to get the New Ai web 2D CAD version finished. Like Jonathan, I get more enjoyment from creating parametric designs — it’s a challenge, almost like solving a puzzle.
Try link again (by Mike C)
@ruevs
I’m in the process of removing all references to SolveSpace and SketchFlat, along with all related code. SolveSpace really should support Name Variables, since many of its users design packaging and would benefit from that functionality.
For clarity: SampleMaker has never been sold commercially — only the Box Library. The source code was always available to anyone who asked under GPLv3, and there may have been a download link for the source about ten years ago. The Windows (.exe) and Mac versions were always free to download.
I’m glad this thread was found now, because I was just about to start a subscription service to the library. It also gives me a push to get the New Ai web 2D CAD version finished. Like Jonathan, I get more enjoyment from creating parametric designs — it’s a challenge, almost like solving a puzzle.
I’m in the process of removing all references to SolveSpace and SketchFlat, along with all related code. SolveSpace really should support Name Variables, since many of its users design packaging and would benefit from that functionality.
For clarity: SampleMaker has never been sold commercially — only the Box Library. The source code was always available to anyone who asked under GPLv3, and there may have been a download link for the source about ten years ago. The Windows (.exe) and Mac versions were always free to download.
I’m glad this thread was found now, because I was just about to start a subscription service to the library. It also gives me a push to get the New Ai web 2D CAD version finished. Like Jonathan, I get more enjoyment from creating parametric designs — it’s a challenge, almost like solving a puzzle.
(no subject) (by ruevs)
The link you provided (https://drive.google.com/file/...eKGduGZBII/view?usp=drive_link) above does NOT fulfill your obligations under the GPL.
If simply contains the SolveSpace source code exactly as it looked in 2.1.rc1 (https://github.com/solvespace/...5120c9d707d1b15f2fe2f56521d30b).
The GPL requires that you provide the COMPLETE source code of the derivative work - your SampleMaker - under the GPL.
If simply contains the SolveSpace source code exactly as it looked in 2.1.rc1 (https://github.com/solvespace/...5120c9d707d1b15f2fe2f56521d30b).
The GPL requires that you provide the COMPLETE source code of the derivative work - your SampleMaker - under the GPL.
What is in there (by Mike C)
Here is what you have
https://youtu.be/l2ziovWV3RE
Now that you have that code now i deleted off google drive. Also have Jonathan email me as that's who copyright. is in the source.
https://youtu.be/l2ziovWV3RE
Now that you have that code now i deleted off google drive. Also have Jonathan email me as that's who copyright. is in the source.
Post a reply to this comment: