I'm now two months into developing my new engine and here's a breakdown of currently working features:
Models and Cameras are scene graph nodes so you can make hierarchies like in Unity.
You can modify shaders and textures while the game is running, allowing fast iteration. This is implemented using a FileWatcher class that registers created objects.
I'm not using any framework, my tests are simple programs that use return codes that are used to generate a HTML report.
D3D11 Shader Reflection
Because my engine has GL and D3D renderers with support for user supplied shaders, I reflect the uniform names and create constant buffers from them.
BMFont is widely used in games industry so I wrote a reader for its ASCII and binary formats.
Texture Atlas support
Supports Texture Packer exported Ogre/CEGUI format.
Useful for iterating containers of models, render queue elements etc. and applying operations on them.