Hi Erwin,
I think this case sounds a lot like what EASE had to do to work with external dependencies. EASE has works-with dependencies for Py4J[1]/Jython[2]/(and other languages?), but those plug-ins are not hosted by Eclipse. However they are referred to by the EASE plug-ins. That methodology works well for EASE because EASE does not ship an Eclipse installation, but just p2 site. When a user installs EASE for Python (Py4J) they get the appropriate Py4J too. This is done with p2 and the way this is achieved is with the jboss tools to make the content.xml files[3,*]. m2e (for Maven) do something similar too, when you open a maven project for the first time, you get prompted to install additional plug-ins. The difference is that EASE's Py4J plug-in depends on Py4J[4], but the third-party Maven related plug-ins just extend m2e extension points. If I understand correctly, the former requires the workswith, the latter doesn't.
> In short I guess I fail to understand what is the real assumed nature of a works-with dependency.
> If it can not be delivered with an Eclipse-approved download, I would think we don’t need any kind of CQ anyway for such a thing?
So, in summary, my understanding is that the works-with is when the Eclipse code depends on the third party code/distribution, but Eclipse is not redistributing it.
Therefore to answer your question by asking you a few questions. Does Triquitrium depend on org.ptolemy.triquetrum.editor.palette (i.e. is there an Import-Package/Require-Bundle referencing org.ptolemy.triquetrum.editor.palette)? If so, you need a CQ. Does Triquitrium want to redistribute org.ptolemy.triquetrum.editor.palette? If yes: need full CQ, TypeA or B, If no: need works-with CQ which can then be "and Later Versions".
HTH,
Jonah
* If you look at the content.xml for EASE you will find references to the non-Eclipse sites to find the missing (py4j/Jython/other) dependencies. For example, you see this at the top of an unpacked content.jar[5]:
<references size="6">
</references>