Normally, when you do a copyright transfer, you're no longer the holder of the copyright, and thus cannot make a copyright claim (in other words, cannot assert copyright in the source code; but can still nonetheless make an authorship claim, as many authors do).
Is there a way to share the copyright, e.g., for a natural person to assign the copyright to some other party on a shared basis, such that both parties could claim the copyright at the same time on the same piece of work? Is it legal?
Copyright Act §13 (1):
...the author of a work shall be the first owner of the copyright...
(2):
Where the author of a work was in the employment [...] and the work was made in the course of his employment by that person, the person by whom the author was employed shall, in the absence of any agreement to the contrary, be the first owner of the copyright
The "author" may be a joint author. Joint authorship means (§2):
a work produced by the collaboration of two or more authors in which the contribution of one author is not distinct from the contribution of the other author or authors
If the authors did not intend to create a joint work, but rather just contributed independent parts to a work, it is considered a "collective work", with each author maintaining copyright only in those parts that are originally theirs. The Copyright Act defines a collective work to be (among a few other things):
any work written in distinct parts by different authors, or in which works or parts of works of different authors are incorporated
§13(4)-(7) The owner can transfer in whole or in part the copyright to another party. The owner can also give a licence to interest in any of the rights protected by copyright rather than an assignment. Licencing is different than assignment (see Euro-Excellence v. Kraft). In the case of partial transfer, for the purposes of the Copyright Act, the assignee is treated as the owner of the copyright with respect to the assigned rights.
Is there a way to share the copyright, e.g., for a natural person to assign the copyright to some other party on a shared basis, such that both parties could claim the copyright at the same time on the same piece of work?
This was partially tested in Euro-Excellence v. Kraft. The issue in that case was that Kraft Canada was sold an exclusive licence to use some work related to the Toblerone brand in Canada. Euro-Excellence imported into Canada and sold products that used the copyrighted work (produced with authorization in Europe). One question was whether Kraft, an exclusive licensee, could bring a copyright infringement suit. The court recognized that "Where the owner of a copyright has granted an exclusive licence, it has temporarily granted a proprietary interest in the copyright itself to the exclusive licensee", citing Copyright Act §13(7). The act gives "the exclusive licensee the right to invoke the Act for copyright infringement not only against third parties, but also against the owner-licensor".
In Canada, splitting of Copyright can happen in a few situations:
I wouldn't call any of these situations "duplication". But, that's just a word choice.
Your linked example appears to be either a work of joint authorship or a collective work, but we lack the information needed to make that determination. Also, the declaration of copyright ownership in your linked example shouldn't be taken as fact. Who actually owns the copyright is not dependent on what is claimed in the file.
Initial ownership, joint authorship, collective works, and partial transfer are largely the same in the US as in Canada. See 17 U.S.C. 201.
Yes: You can share ownership, and you can list multiple owners in a copyright notice (here is an example), but you don't have to.
You can think of a copyright in a creative work as being like a bushel of wheat. You can easily split that bushel up into four pecks, keep one yourself and hand the other three over to other people/entities.
This is done all the time in music copyrights, where you have a song co-writer...each owns 50% of the copyright. That song is then contracted with a publisher...now the publisher owns half (for example) of each of the co-writer's shares.
The result of this split is that the revenues generated by the copyright are split according to the copyright splits.
I might mention that the numbers I selected here for examples are completely arbitrary, and can be split out however the parties may contractually agree. One might have 100 members of an ensemble that agree to each hold 1% of the copyright, or conversely one might find an ensemble where one person holds 90% of the copyright and the other only 10% (certain co-written songs of Madonna and J-lo and Beyonce come to mind...).
One additional point...copyright is not quite the same thing as authorship. They're intrinsically intertwined, but authorship puts credits in your CV, while copyright puts credits in your bank account.
Let's take one other example: You write a book. Your wife then divorces you. In the negotiated settlement you assign 25% of your book copyright to her. You now own 75% of your copyright, she owns 25%. If money is made, she gets some, you get some. You both own copyright
Yes, its called a licence.
You can licence any of your IP (including copyright) to anyone on any terms.
A common example is a geographic licence; a book publisher in the UK licences one publisher the North American rights, another the European rights and another the Australia/New Zealand rights. This is so common in the publishing industry that long-term ongoing relationships are established so that this happens for all published works.
Yes, and yes it is legal. Copyright occurs automatically at the creation of a new work ¹. If two or more people jointly create a work, they are joint holders of the copyright, with equal rights. In general, copyright holders have the exclusive right to do and to authorize others to do the following:
In terms of enforcement, determining jurisdiction is extremely important. The standard for determining jurisdiction is now known as the Calder test, Calder v. Jones (1984).
