Some highlights include HTML5 Microdata work and network latency improvements on the Core side, and new QRESYNC support for Opera's mail client, M2.
For those not familiar, QRESYNC is an IMAP extension that enables you to synchronize message metadata using much less overhead. It allows clients to request all changes since the last time they were connected, instead of having to check each message for changes. Not all IMAP servers support it, but Opera's Fastmail and My Opera Mail of course lead the way. This change should be particularly welcome for users on capped or slow connections.
This build also contains improvements to the database backends used in Opera's mail client, M2. They will now create less fragmented files, allowing for faster writing and retrieving of data (though this does not apply to upgraded mail profiles).
One small extra point with regards to the Core network latency fixes, just to avoid confusion. You will not see any real difference testing against popular benchmarks (which focus on rendering and JavaScript performance); this kind of work is more likely to have an impact on regular "day to day" browsing. However, it can result in pages loading in half the time! up You are most likely to see a difference if you have a poor network connection and others may notice improved performance when connecting to a webserver hosted on another continent.
