John Robertson of JISC CETIS has overviewed developments in major digital repository software in his "Repository Software Update" post.
Here's an excerpt:
Over the past couple of months I've had a chance to hear updates from a number of repository software developers (at a Fedora training day, at DEV8D and on a number of blogs). Albeit slightly delayed by holidays, here's a bit of a snapshot of where ePrints, DSpace, Fedora, Microsoft's repository are at. There's a lot more information about Fedora than the others as I've heard a couple of updates from them. The usual caveat that I may have misunderstood what some of these are or how developed they are should apply. Much of this development is building up to releases at Open Repositories 2009.