Johannes ... the bare calendar package and acs-events package it is based on work great in OpenACS 4 at the moment, both Postgres and Oracle.
One of my upcoming tasks, for a client, will be to generalize the calendar package so it can track *any* object derived from acs_events, rather than just the calendar object type (the acs_event type has all the time and date information needed to display calendar events).
I also have a copy of the 3.4-based room reservation package mentioned above.
The cool thing to do would be to rewrite the room reservation package to use the standard acs_events data type and massage it in whatever other way is needed to make it work well within the OpenACS 4 framework (expose it to the search package, for instance). By basing it on the standard OpenACS 4 acs_events data type the reservation could then be easily added to the right calendar (AFTER I make the changes to the calendar package mentioned above, which will happen in the next two weeks).
A lot of people would love to have this. I've not looked at the code for the room reservation system so don't know how closely tied it is to the old intranet package. It should be generalized in any case if it is.
If you're interested in working on this, e-mail me privately and we'll talk things out...
