> A derivative work is a work based on or derived from one or more already existing works. Common derivative works include translations, musical arrangements, motion picture versions of literary material or plays, art reproductions, abridgments, and condensations of preexisting works. Another common type of derivative work is a “new edition” of a preexisting work in which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work.
The viral licenses of open source grants that to anyone who also follows the same license rather than requiring the equivalent a playwright to contact the right holder of a novel to ask permission to use their story as the basis for a play.
And then, as a derivative work... if someone wants to make a movie based on the play, they need to contact the playwright and the author novel and get permission again.
The restrictions of the original novel's copyright have extended beyond its original bounds of text on paper to a play and a movie.
If your work includes another's work, it's not just your work. If you included proprietary code in your work, it would also impose restrictions on the combined work.
If ^ that imposes restrictions on the combined work, it is a viral license. Because it spreads beyond its original bounds.
They absolutely do exist.