Do may LD developers use existing game frameworks and collaborate on improving those frameworks?

For example have you seen an amazing LD entry and considered working with the developer on creating a framework for that genre of game?

Or are the best entries already using good frameworks built on their technology stack e.g. Unity / Haxel / Monkey / BlitzMax / Java / C# / C++ / Unreal / Cryengine etc?

OK this would only work if your game worked within or close to a given frameworks genre e.g. FPS, RTS, Platformer, 2D/3D, Racing, Flight so it might reduce the diversity of Ludum Dare entries but I would think it would increase the quality of entries quite a bit.

What do you think, is LD all about re-inventing the wheel or could it be about improving different styles of wheel for different jobs?