The advantage of Processing (www.processing.org) is that it supports very rapid development of 2D and 3D graphical primitives. It obviously gives up some efficiency (I'm actually a C/C++ programmer for my day job), but gains a lot for rapid prototypes.
Here's a screenshot of it logging data from my '02 WRX... right now, it only does digital dash and no file logging, and the parameters are hard-coded, but I'm in the process of working on an intuitive GUI to set up the layout and graph types of the dash.
Without further ado, a quick screenshot:
/Andrew
