While considering how to actually get a machine built out of the simple level physics actors and joints, I basically have two options. Either use a data driven machine description (probably an XML file) or use a scripting language to directly create the combinations. There are of course pros and cons for each, but ultimately I have decided to go with scripting...
The original Hieroglyph library had a very simple scripting interface for Lua. There were basically a few methods for loading and running files, but little other interactivity between the script world and the application side of things. However, the FeedBack object hierarchy is going to be pretty complex and will likely require easy communication between the objects on both sides of the scripting boundary. So, I will be adding a more sophisticated scripting interface into both Hieroglyph 2 and 3.
The primary language feature that I am going to use is the object oriented facilities in Lua. If you haven't spent the time to get to know Lua, you owe it to yourself to visit www.lua.org and give it a try. There are online books available, and the community seems to be relatively friendly to newcomers.
The language itself is a fantastic experience - its both simple and complex, compact and expandable, standalone and embeddable. It would seem paradoxical, but it really is a pleasure to discover all of the intricate features that the authors use to allow you to implement more complex features. Object oriented support is available, but not required. Its pretty cool, so go take a look!
I myself still need learn some more details about how people use lua in a game setting, so I ordered a copy of Game Development with Lua. It looks like it covers a few different areas, and I'm hoping it will be descriptive about system design to share objects co-existing in both languages... As I flesh out the system, I'll be sure to post the details to see what you think.