Since various people were curious to see especially the little query language we wrote on top of the Zope 3 catalog, I've just put up the generic libraries we developed for documentlibrary project online, at least in svn in the Zope 3 base at codespeak, here:
I've done this in the "tradition" of Zope corporation's placing of zope.formlib and zc.catalog in the Zope svn repository. That is, we at Infrae feel the libraries are useful and want to share them to obtain feedback, but more communication and work is necessary before these could be accepted into common codebases like the Zope 3 core or the Z3ECM project. And if pieces don't end up there that's fine too; it works just fine as an independent library right now.
The hurry library ("written because we were in a hurry to use these features") contains:
higher level query system built on top of the Zope 3 catalog. Some inspiration came from Dieter Maurer's AdvancedQuery for Zope 2. See src/hurry/query/query.txt for documentation. Is undoubtedly still much less powerful than Dieter's system for Zope 2, and isn't very optimized, but does make using the catalog quite a bit more pleasant.
a simple but quite nifty workflow system. See src/hurry/workflow/workflow.txt for documentation.
advanced file widget which tries its best to behave like other widgets. See the doctest in src/hurry/file/browser/file.txt for some documentation.
On the workflow system I need to make an extra comment. We are aware various powerful workflow systems are under development for Zope 3. At the time we started the documentlibrary project however none of them seemed fully baked. After some communication with some of the people working on the workflow systems and realizing none appeared ready, we decided to quickly roll our own.
I like its simplicity and it supports quite powerful features, such as multi-version workflow. It's entirely geared towards the featureset of the documentlibrary application we're working on but is generic enough to be also applicable in other contexts. It's however no match for the systems that are currently being brewed up for Zope 3.
Have fun with hurry! Let's try to channel discussion on this through the zope3-dev mailing list for the time being.