The two main features are: an improved and more flexible anti-flood block and channel history which can now be stored encrypted on disk and allows clients to fetch hundreds/thousands of lines.
See the release notes for full details on these and other new features.
As always, you can download UnrealIRCd from https://www.unrealircd.org/
EDIT few hours later: download updated, so it actually works
![Very Happy :D](./images/smilies/icon_biggrin.gif)