Many C/C++ game development demos and apps tend to use the
popular AntTweakBar parameter tweaking library. AntTweakBar is
used to manipulate user-defined parameters in real-time by
providing a GUI-like interface in an OpenGL / DirectX environment.
AntTweakBarD[1][2] is just a simple D binding to this library.
Note: If you prefer to load the AntTweakBar shared library lazily
(Derelict-style), you may perhaps have success using the Deimos
Dynamic Loader[3] (not tested with this project).
Have fun, and let me know if there are any bugs!
[1] : https://github.com/AndrejMitrovic/AntTweakBarD
[2] : http://code.dlang.org/packages/ant-tweak-bar-d
[3] : https://github.com/jkm/ddl