[chat] Looking for a web-based bibliography database/system

[Mary <mary-slug@xxxxxxxxxxxx>]

Hi everyone,

I'm looking for a Free Software program that does some/much of the
following:

Essential:

 - helps in constructing a web-based annotated and categorised
   bibliography

   By this I mean it helps construct webpages that track academic
   papers, with all the usual bibliographic information (authors, title,
   year, journal, page numbers...), and allows papers to be categorised.

Bonus points for:

 - being implemented in Perl, Python or Java (just because my host
   provides them).

 - allowing summaries or notes (a surprising number of bibliographic
   databases don't allow this, they're just fancy frontends to BiBTeX).

 - tracking references in both directions (what papers cite X? What
   papers does X cite?)

 - categorising entries

 - searching on all kinds of fields and combinations of fields

 - letting you link to online copies of papers

Does anyone know of such a beast?

Now I realise that this would not be impossble to code myself, but I'm
not so excited about the prospect of coding it that I'd ignore existing
solutions.

-Mary