You and I are talking about two related but separate use cases, I
think.  Yours: user writes code with docustrings in PyDev project;
docustrings are parsed when code is 'compiled' and stored in
resource somewhere (XML file?) for later lookup.  Mine (Java case):
user includes rt.jar file, makes association with javadoc directory
in project settings (see attached picture).

No attached picture arrived... (Still, you probably have the src to the rt.jar -- in the preferences, at java > build path > classpath variables > JRE_SRC), my guess is that if you don't have the sources, you'll also not get the javadoc for it.

"So, what I thought was to make the javadoc available in the help...
The hovering is probably going to work on the same base that the
code-completion works, getting the docs from the code itself..."

For the python case, I guess this would work (but not in the Java
case as the jar files don't have comments).  I wonder, though, if
we can leverage the javadoc file association as in the case above?
Not quite the same, is it, since there's nothing to associate the
javadoc with? Guess I see the point now. It's possible that even in
the case where the rt.jar <-> javadoc association is made, the
javadocs are parsed into a lookup structure rather than relying
browser HTML navigation. Too much of a newbie to know, myself.

(as I said, they probably rely on the rt.jar code that is associated in the Eclipse variables -- I think that in python we would follow that path, as you already have access to all the pydocs when doing code-completion, so, having a javadoc for python would not really help us...)

Got an ant build file or .project/.classpath pair?   Can't figure
out which modules I need from CVS... looks like some old stuff in
there.

Actually there are several projects you need to download that make the whole pydev...
Namely:
org.python.pydev
org.python.pydev.ast
org.python.pydev.core
org.python.pydev.debug
org.python.pydev.feature
org.python.pydev.help
org.python.pydev.jython
org.python.pydev.parser
org.python.pydev.templates

the xxx.site and xxx.releng are optional... they are used only if you want to create a pydev distribution... the other projects in the cvs should be dead by now ;-)

And if you are compiling the tests too, you have to create a file named org.python.pydev.core.TestDependent.java (in the tests source folder). There is a file named TestDependent.template that can be used as a base for it (there are many system-dependent things that have to be specified for running tests)...

If you grab them with the Eclipse cvs, choose those folders and ask Eclipse to make download them as new projects in the workspace... It should configure things correctly automatically.

(mental note: I have to create some place in the homepage explaining this better)

So, if you need something else, just ask.

Cheers,

Fabio