I have been asked to clone some existing software for a company. Basically its an old 16 bit DOS console app, which was supplied free of charge in I believe the late 80's. Having replaced the machine that needs to run it with a box running Win7 x64 they can't get it to work. It crashes every couple of minutes under DOSbox.

The company that supplied it appears to no longer exist - if they did the company asking me to do this would almost certainly know about it. Its undetermined whether they have gone entirely or are just trading under a different name. If the latter they seem to have withdrawn from the market related to this product (because again, niche area, we should know about everyone there).

What is the status to this with regards to copyright etc.? The main concern for the company involved is they want an identical interface to what they already have so I would have to clone this entirely. Having no source code / indication of the underlying mechanisms these would be written from scratch.

Is an interface covered by copyright? / Does that still hold 30 years later? What is the assumed license when none at all is provided?

Under UK law would I be under any serious risk were I to take on the project? How would this pan out if I then decided to sell the software on to other companies?

  • 1
    Did I get you right, you are talking about a console APP with a command line interface? Or are you talking about an interface with dialogs and forms? And if its the latter, why don't you just create a similar graphical user interface instead of an identical, character based inteface?
    – Doc Brown
    Jun 7, 2014 at 6:24
  • You were right, its a CLUI, so whilst I can change the name of things slightly menu options (numerical selections) have to be identical. There are even options the company doesn't use which gives me a choice of menu options of 1,2,7 etc. Or leaving them in making it even more obviously a clone.
    – Hector
    Jun 7, 2014 at 17:25
  • IMHO the risk is small that someone ever will sue you because you create a program having some command line switches like the original one. There is typically no copyright for a single word or word fragments, see techdirt.com/articles/20110412/11105613870/…. Though I may be wrong if the program has an interface with a complexity comparable to this: imagemagick.org/script/command-line-options.php
    – Doc Brown
    Jun 7, 2014 at 17:31
  • Thanks :) Its quite complex, but I think hopefully on the safe side.
    – Hector
    Jun 7, 2014 at 19:53

3 Answers 3


What is the status to this with regards to copyright etc.? The main concern for the company involved is they want an identical interface to what they already have so I would have to clone this entirely. Having no source code / indication of the underlying mechanisms these would be written from scratch.

Is an interface covered by copyright? / Does that still hold 30 years later? What is the assumed license when none at all is provided?

What is the status to this with regards to copyright etc.?

Legal questions are best asked of someone familiar with the ins and outs of the various aspects of intellectual property law in your jurisdiction. Asking random people on the internet is not legal advice and shouldn't be construed as legal advice. Everything that I'm going to say below is based on the US understanding of legal issues by a layman - the US because thats were most of the software court cases have been. You're in the UK - talk with a local legal expert.

Copyright protects the specifics works. The actual source code. The graphics resources used in creating the application. The music that the app plays. The text in the help pages in the app.

The look and feel of an an application sits on some confusing ground. Icons can be copyrighted. In Lotus vs Borland the menu was at issue. The outcome of the case was that the implementation is subject to copyright, and the icons in a menu may be copyrighted, but the operations and mechanics are not copyrightable.

Neither are they patentable (one might get a design patent on various aspects of how things look... but thats very unlikely for an old 16 bit DOS app). And they aren't able to be trademarked either (one might be able to trademark specific words in the menu such as "About Frobnostic..." where Frobnostic is the trademarked name of the app).

You are starting out from scratch, doing a clean room design (or nearly so). You are probably in the clear.

  • Thanks! Tried to upvote, haven't yet the reputation . I'll ask some law friends tomorrow on it, but considering this law usually involves some kind of international concern knowing I should be OK under US (which is usually stricter / further enforced) is reassuring. I've since posting discovered the company was brought by a large American international in the early 90's along with several similar ventures. They then managed to buy themselves out and operate under one of the other companies names and no longer in our field. So i'm considering just dropping them a polite email explaining.
    – Hector
    Jun 7, 2014 at 2:29
  • Right now Oracle is suing Google for about $8 billion right now to answer a similar question. See here eff.org/cases/oracle-v-google for more info May 7, 2016 at 1:12

The clean, simple and practical answer is: Just make it, don't rock the boat and don't draw attention to it. Get some something written down from your superior so you can always have a paper trail to cover your back. The more questions you ask about the legality on open forums the more attention you potentially draw to it and you may cause problems where there were none.

As long as it is only used within your company, the chance of anyone outside finding out that you made a clone is close to 0.

This may not be the most ethical answer but it's practical.

  • 1
    This is a non-answer. You're speculating upon whether the person would get caught and not addressing the core of the question.
    – user53019
    Nov 7, 2014 at 12:42

Well, you got lucky. I practice IP law. Yet to hedge, I practice patent law, not copyrights, and this is a copyrights issue. (The USPTO would no grant patents on software until recently, and even so any patents from the 80s have long sense lapsed and are rendered unenforceable.)

So the short answer is it depends. The mere fact that someone wrote that software means there is an inherent copyright. Filing a copyright at the Library of Congress just establishes a date for litigation later, but the mere act of creating original work renders a work copywritten, so long as it is minimally creative and tangibly recorded. A copyright from the 80s IS still enforceable. Copyrights have much longer terms than patents and do not require the maintenance fees patents do.

Honestly, based on what you just told us, it appears you would be infringing as you've met the three prong test of copying, similarity, and appropriation. The question then becomes is your version of the software fair use. ... this is a very tough question to answer. I would guess you are ok because you will on some levels be transforming the main work and (most importantly) you won't be harming the market for the original work. The doctorine of fair use will likely protect you from any unfavorable judgment if you get sued, so lucky you again. Read up on fair use here, as this is one of the documents I used to brush up on my copyright law (sorry, I'm not going to do the leg work to look up the statutes and case law and decode them for you, lol). http://www.kentlaw.edu/perritt/courses/seminar/papers%202009%20fall/Susan%20Estes%20Seminar%20paper%20Final.pdf

Lastly, THIS IS NOT LEGAL ADVICE; I AM NOT ACTING AS YOUR ATTORNEY. This is general advice and I decline any liability based upon any actions you take in furtherance of this information. I have not researched this further than what I remember from school, and I haven't really looked back since. Write you code at your own risk. :) After all, why would I risk getting sued for malpractice without you paying me when I'm trying to be helpful to a stranger discussing subject matter I haven't studied in 10 years? :)

  • 1
    Given Lotus vs Borland on the copyright nature of a user interface, and a clean room design, wouldn't these satisfy the issues of copyright?
    – user40980
    Jun 7, 2014 at 14:02
  • Thanks for the Input James. Obviously i'd never take anything on the Internet as concrete legal advice, Simply asking here lets me know whether I should abandon ship immediately or gives me a little more confidence that I'm not at risk. @MichaelIT I'm not sure whether clean room design applies on the interface - I have it in front of me and I clearly aim to copy it if I go ahead. The internals i've been acting entirely on the assumption I will be safe - they will be developed completely independently. Lotus vs Borland looks promising.
    – Hector
    Jun 7, 2014 at 17:32
  • @user2036256 the clean room design doesn't apply to the interface at all - it applies to how the application behind the interface works. You are working from the specification - "the app does X, Y, and Z" rather than "the app does this system call, that system call, and then this other system call." You are not disassembling the application but rather creating a new work that does the same thing. As mentioned, the protection for "an application works this way and uses these algorithms" is covered by patent law, not copyright law - and those (if any existed) would have expired by now.
    – user40980
    Jun 8, 2014 at 0:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.