PLoS is building its innovative PLoS ONE e-journal, which will incorporate both traditional and open peer review, using the open source TOPAZ software. (For a detailed description of the PLoS ONE peer review process, check out "ONE for All: The Next Step for PLoS.")
What is TOPAZ? It’s Web site doesn’t provide specifics, but "PLoS ONE—Technical Background" by Richard Cave does:
The core of TOPAZ is a digital information repository called Fedora (Flexible Extensible Digital Object Repository Architecture). Fedora is an Open Source content management application that supports the creation and management of digital objects. The digital objects contain metadata to express internal and external relationships in the repository, like articles in a journal or the text, images and video of an article. This relationship metadata can also be search using a semantic web query languages. Fedora is jointly developed by Cornell University’s computer science department and the University of Virginia Libraries.
The metastore Kowari will be used with Fedora to support Resource Description Framework (RDF) http://en.wikipedia.org/wiki/Resource_Description_Framework metadata within the repository.
The PLoS ONE web interface will be built with AJAX. Client-side APIs will create the community features (e.g. annotations, discussion threads, ratings, etc.) for the website. As more new features are available on the TOPAZ architecture, we will launch them on PLoS ONE.
There was a TOPAZ Wiki at PLoS. It’s gone, but it’s pages are still cached by Google. The Wiki suggests that TOPAZ is likely to support Atom/RSS feeds, full-text search, and OAI-PMH among other possible features.
For information about other open source e-journal publishing systems, see "Open Source Software for Publishing E-Journals."