For software preservation reasons, I've been trying to sort out the licensing for a lot of 40-year-old CP/M code with an intent to liberate as much as possible.

Back then formal licensing was very rare, and what we now call open source was handled on a very informal basis by 'public domain' libraries. (Very little was actually public domain.) People would donate things they wrote to the libraries for redistribution. Except, there was hardly ever any kind of actual license.

Here's an example of the kind of thing I'm dealing with:

;(805) 527-9321 (MODEM, CP/M-NET (TM))
;(805) 527-0518 (VERBAL)

(From http://www.retroarchive.org/cpm/cdrom/SIMTEL/SIGM/VOLS000/VOL005/CPUDIAG.ASM.)

So: it's got a an actual copyright declaration; there's a statement that it's been donated to a user's group; there's no actual license; the original author is unlocatable and potentially dead; the user's group itself has no formal licensing or even documentation other than a few text files describing which archival tool to use, and no longer exists outside archives (see http://www.retroarchive.org/cpm/cdrom/SIMTEL/SIGM/VOLS000/VOL000/).

(This is actually unusually clear, as there's a statement in the source that it was actually donated. Frequently there isn't.)

I've been very cautious and have been going by the principle that if I can't locate the actual author and persuade them to put a real open source license on it, I can't use it.

Is this actually true? Is there any basis behind the frequently-expressed opinion that as it's been freely distributed for 40 years then it's legally safe to continue to do so?

I'm pretty sure there isn't: while you could plausibly argue that the author's intent is clear, in that they wanted the software distributed, there's nothing indicating the terms of distribution. (Non-commercial use only statements were pretty common back then.)

But I'm an engineer, and tend to think in terms of rules. Second opinion, please? I'd love to be wrong here.

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    "the frequently-expressed opinion that as it's been freely distributed for 40 years then it's legally safe to continue to do so" Could you give some indications of where you've seen this? I've never heard precisely that claim. Jun 4, 2019 at 13:52
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    @PhilipKendall Mostly CP/M forums --- would rather not point to specific examples as it's in conversations I'm currently having (which prompted this message). But I get a lot of people who say: "It's 40 years old, nobody cares any more, just do what you like". Jun 4, 2019 at 14:36
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    IMO, there's a big difference between "nobody cares any more" (a guess at what people are going to do) and "legally safe" (a statement that even if people do care, they can't do get you in trouble with the law). Jun 4, 2019 at 14:37
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    Hmm, possibly --- not necessarily a useful one for me, though. For clarity, my win condition here is: free enough to be accepted into Debian. (I want to make a package of CP/M-ish software which can be shipped with emulators.) Jun 4, 2019 at 15:50
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    "DONATED TO THE "SIG/M" CP/M USER'S GROUP" - To me this means is not an "implicit" license but an explicit license for the "'SIG/M' CP/M USER'S GROUP" to use it and possibly which would allow that particular group to redistribute it. I.e. I don't see how you could interpret this as a license giving permission to anyone else to redistribute it.
    – Brandin
    Jun 7, 2019 at 7:33

1 Answer 1


There might be such a thing as implicitly-licensed code, but if there is, old age doesn't make it so. Under the Berne Convention, the exploitation rights to any creative work are reserved from the moment of the work's creation. Old code whose current rightsholder is unclear is known as abandonware; like any other copyright work which has not been clearly relicensed, the rights in it don't disappear until the normal expiration of copyright. In the EU, the Orphan Works Directive has made tentative moves towards dealing with the problem for some classes of work, but it's not clear that it covers software, and in any case it permits a rightsholder to emerge down the road and terminate a work's orphan status. The US lacks even this tentative approach.

You clarify that you're interested in getting this into Debian, by which I presume you mean into main. I think you're right to note that it is vanishingly unlikely that any rightsholder will emerge to claim ownership of this code, but Debian are famously punctilious about freedom. Since DFSG guideline one requires that the work be freely redistributable, and abandonware isn't, I doubt that you will be successful. non-free seems to me to be a perfect place in Debian for such works, but I'm no expert on the Debian ecosystem and I could well be wrong about that.

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