I'm still pursuing the theme of an existing sophisticated code base to enable supporting multiple versions & formats of our eBooks (user-contributed, curated, edited, masters and revisions). Last week I had mentioned looking at TRAC. That is a tool that layers over version control systems like Mercurial or git. I've also been looking at DSpace, which I'm in the midst of rolling out for my campus (i.e., day job), and I will try to ingest all of the files & metadata shortly. However, DSpace does not yet have versioning capability, which I think will remove it from consideration. Two others I'm taking a dive into are Notre DAM (http://www.notredam.org/) and ResourceSpace (http://www.resourcespace.org/about.php). Although these both seem more geared towards photos than eBooks, they do have a suite of transformation capabilities, and accept user contributions. I found a recent comparison of such "digital asseet management" systems here: http://www.opensourcedigitalassetmanagement.org/ It would be great to hear of anything people know of these or other existing systems. At the same time, I know people are looking at using other existing tools that are more general. -- Greg