The most important changes are:
Photon now supports the .NET 4.0 runtime and puts it to good usage: The (much) improved ThreadPool was able to get us 15 to 20% better results in load tests! Keep in mind: without changing a single line of code. For the time being we keep Photon, Lite and MMO compatible with DotNet 3.5 but from now on you're free to use new features as well. You can use Visual Studio 2010 (and still VS 2008) to edit and compile your projects.
We support the new Unity3D version 3 out of the box (our 2.x server did this already). Policy requests are answered by the built in policy application. We deliver the Unity samples in Unity 2.x format just to stay compatible – but you can easily load and update with the latest v3.
We simplified the deploy of Photon applications. So far the deploy process was: Stop Server, Deploy, Start (assemblies were locked as the server runs). Now we use shadow copies and you can just XCOPY your new assemblies to the server and your application (domain) gets restarted.
As always, we've been optimizing the C++ Core as well: Photon got new buffer allocators which give us better memory usage across the board, without any performance hit.
The API was extended by a Flush method to send out packages instantly. Usually, Photon has a small send-delay for anything that's going out to accumulate some commands that go to the same peer. With Flush, your game logic has the power to override the delay and speed up replies / events where needed.
For a long time, we wanted to show you what's happening within your Photon server. We updated the Dashboard to do just that: Once started, the Dashboard makes Key values of Photon available via webbrowser. Track CPU usage, memory, connections and more.
You can now configure multiple UDP and TCP listeners to open Photon for different IPs and ports. This is in use for server-to-server communication and a stepstone for load balancing.
Server-to-server communication also made it into this release. As part of the socketserver lib (photon.socketserver.dll), it's becoming best practice to sync multiple instances of Photon. We will show more of that in a while.
Next up: Encryption!