HTC's posted a nice fat package of code on their developer portal, labeled "HTC Hero Kernel Source Code." This isn't nearly as tantalizing as it sounds, but it's pu-ret-ay exciting nonetheless. Here's why:
The Hero's kernel is the bottommost part of its software; it's the part that manages basic functions like memory allocation, device drivers and the like. For modders to be able to access and compile this is great news for potential Hero modders, who'll be able to drop this kernel into cooked ROMs with all manner of interfaces, app configurations, performance tweaks and the like. What this won't do is help bring features like the Sense UI to other handsets—though modders are doing pretty well with that on their own—because those components are distinct from the kernel.