In particular, a new audio engine is on its way. Anyone with experience of Godot 2.1's audio engine knows that this alone is some incredible news.
Godot 2.1 currently uses samples and streams as two separate concepts. This gets a bit messy sometimes, given that some things such as music, dialogue or other "one-off" effects benefit from being set as streams while other things may benefit from being samples. Keeping track of both a SamplePlayer and a StreamPlayer can get confusing.
Godot 3.0 is simplifying this process by only supporting streams. This isn't as detrimental to performance as it sounds, as the appropriate optimizations for each are still being made.
Additionally, Godot 3.0 is adding functionality for much easier integration with C++ modules. This is coming by way of GDNative(formerly known as DLScript), a kind of bridge between external libraries and the Godot engine itself. This is also huge, given that now recompiling the engine is no longer necessary for the sake of integrating with things like Steamworks.
Image courtesy of AlisterCat
On top, they are re-writing the rendering engine to be both faster and more versatile. Particles can now be GPU accelerated! For those of you who don't know- this is another incredible feat. This means that particles are now very cheap to render en masse!
There is even some experimental functionality to export to WebAssembly. This is the feature that I am most excited for in Godot 3.0.
Of course, that's not to say that Godot 2's HTML5 export option is unusable. It's not. I ported my game, Super Displacement, to HTML5. While it does work, it is notably slower than the desktop edition and sometimes the scoreboard inexplicably doesn't work. You can check this for yourself below.
Shameless self-promotion aside, I've been using Godot 3.0 straight from Github. It's a little bit buggy sometimes but damn, it feels good to be able to make use of the above features! If you want to, it's fairly simple to compile it from source. You can find the instructions here!
The instructions to compile Godot 3.0 on Linux/BSD are wrong if you are using openssl version >= 1.0.0. Trying to compile using a simple scons platform=x11 will result in an error. In fact, you need to use scons platform=x11 builtin_openssl=yes use_llvm=yes.
All in all, Godot 3.0 is going to bring with it an up-tick of popularity, which means an up-tick of documentation and community, which helps to alleviate one of Godot's largest criticisms at the moment- that it has a small userbase.
If there ever was a time to get excited about the Godot engine's success and getting it popularly counted alongside Unity and Unreal, this is that time.
Either way, thanks for reading! Check back in 2-3 days' time for a post on why composing music for your game is not an impenetrable, monolithic task.