The new release switches to vibe-core by default* and compiles on the freshly released DMD 2.079.0. It needs to be used together with the latest vibe-core pre-release, because instead of std.experimental.allocator, which is still undergoing frequent API changes, the forked semi-stable variant stdx.allocator is being used, and both libraries need to match up in that regard. This version contains a fix in URLRouter that can heavily reduce the memory usage of processes that define many routes.

Full change log: https://github.com/vibe-d/vibe.d/blob/master/CHANGELOG.md
DUB package: http://code.dlang.org/packages/vibe-d/0.8.3-rc.1

* It's still possible to use the old core implementation by choosing a different configuration for vibe-d:core:

dub.sdl:

dependency "vibe-d:core" version="~>0.8.3-rc.1"
subConfiguration "vibe-d:core" "libevent"

dub.json:

"dependencies": {
  ...
  "vibe-d:core": "~>0.8.1-rc.1"
},
"subConfigurations": {
  "vibe-d:core": "libevent"
}