After several months of hard work, we finally cut a release of Review Board 1.5 beta 2! This is a much more stable beta than 1.5 beta 1, and includes some new usability improvements, new features, many bug fixes, and a new public API.
One of the nicer improvements in this release include the new diff viewer comment flags, which span the range of lines that the comment was made on instead of only pointing to the first line in the range. This is much nicer looking and much more usable. They also no longer overlap the line numbers, so it's easier to see what line is being commented on.
The largest change in this version is the new REST API. We've had a public API for a long time that worked on a resource model, allowing third party applications to interface with Review Board, but it was hard to maintain and had many warts. The new API is actually a RESTful API, meaning that it's fully resource-based, uses standard HTTP methods and HTTP response codes, is largely self-documenting, and every resource links to related or child resources.
There isn't any documentation yet for this, but we'll be working on some before the final 1.5 release. We'd like to encourage developers using the existing API to begin supporting the new one. You can start browsing the resource tree by pointing your browser to your site's /api/ path. If you're using Firefox, you can use the fantastic JSONView extension to better browse the tree.
Many things were fixed in this release and I'd like to thank everyone for providing feedback, reporting bugs, and submitting patches.
Going forward, we may have a third beta in order to finalize some of our API code and fix most of the remaining bugs, and then we'll try to crank out the release candidate and then final release as soon as we can.
More information can be found in the release notes.