Here is zNote, a web-based bibliography-management tool built with Zope and XML.

zNote is intended to ultimately be a replacement for tools like EndNote, ProCite, and to a certain extent, bibTeX. It uses a hierarchical XML data format which is more flexible than flat data, and it works using a set of pretty simple DOM calls to format, edit, etc.

zNote is currently at version 0.6.2. It is now a complete, functioning Python-classed product. It is totally usable (I have a couple of hundred entries in the one I'm using), but it has some rough edges that could be sanded off. You can read more about those rough edges in the installation instructions.

zNote requires the ParsedXML v1.2.1b product. I haven't yet tested 1.3, but it should work fine, since my use of ParsedXML is totally generic.

It imports and exports data to raw XML easily, so your data is never stuck inside this tool, so you can easily run/synchronize multiple instances

I keep a version on a server and another on my laptop, and periodically reconcile the versions, depending on where I've been.

zNote should be pretty much self-describing and usable right out of the box. I'm including here a sample XML file so you can see what it looks like. Otherwise, you can just start adding entries to it. Please let me know how it works for you.