Technlology Preview 2 :
- Rewrite UI in QtQuick, with full-window OpenGL editor.
- Streamline the definition system, with undo and events.
- Switch all noise generators to FractalNoise, and restore detail-based fractal levels.
- Implement copy-on-write on definitions (to avoid copying whole heightmaps for instance).
- Add clouds to OpenGL with 3d textures.
- Refactor medium traversal to unify clouds, atmosphere and god rays.
- Fix potential holes in land rendering (OpenGL and software).
- Fix sun size not being consistent between opengl and software.
- Remove Qt dependency in OpenGL renderer, except for OpenGLFunctions.

Technology Preview 3 :
- Alter aerial perspective using estimation of the amount of light left after cloud layers traversal.
- Fix rendering when inside a cloud layer, with other upper or lower layers.
- Fix the moon being backlit by its own light.
- Clouds should keep distance to ground.
- Allow render saving in HDR compatible format.
- Add fresnel effect to specular lighting.
- Add shadow control ("minimum lighting") to material.
- Start using OpenCL to optimize rendering.

Technology Preview 4 :
- Implement Sub Surface Scattering for water, textures and clouds.
- Implement earth curvature.
- Use bicubic interpolation for antialiasing.
- Add translations.
- Find a new licence.

Release Candidate :
- Polish all features and UI.
- More translations.