Metadata support

Hi there, first post in the forum. This looks like a fantastic system. I'm looking for something that I can recommend to a local history society with a collection of around 10,000 images. I've up till now been looking at the open source DAM systems but finding that they charge a lot of money (for the society at least) to create a publishing system that will share the images with the local community. Obviously beggars can't be choosers but in order to do the right thing for the library there are some features that are required, those being mostly around image metadata.

I'm particularly keen to know the state of Gallery 3 with regard to reading and writing metadata either IPTC or XMP, and either embedded or sidecars. The library would need to allow trusted and trained members of the community to be able to add metadata annotations to the files. Another feature that would be beneficial would be the ability to track changes to the metadata in the catalog. A version history of sorts.

I've had a search in the forum here and can't clearly ascertain an answer so any help or pointers would be much appreciated.
Thanks