Greetings Drupal site-builder/developer community,
I've been asked to check if anyone here has some additional ideas, besides the modules I've considered already, which could help with an interesting pro bono project (volunteer-work for a non-profit / museum) our company, Cocomore, has agreed to work on. We hope to do something really cool that will show off what can be done with Drupal... but it would be nice if we can achieve our requirements without doing a lot of expensive custom development that might not fill a very common use case... especially if we might be reinventing the wheel. Of course, we hope to contribute any custom code we write for this project, too -- a new contrib module or two, but only if there are good possibilities for re-use.
The main issue is how to graphically represent the complex relationships between a group of parent, child, and "sibling" objects, with multiple levels of hierarchy (and possibly as many as 10 or more parent or child objects related linked to one evolutionary "snapshot" of a project). One interesting module that's in development is the Graph API, which could possibly be combined with some nice rollovers, like BeautyTips or Apture to add a bit of extra richness and interest:
http://drupal.org/project/apture
http://drupal.org/project/beautytips