Generating cross-hatch infill
-- Main.AdrianBowyer - 25 Feb 2008
The Java Software Preferences File page explains various options that effect cross-hatch infill. Hopefully that explains in enough detail that software to implement all that will be relatively self-evident.
The other things that the RepRapHostSoftware does at this stage will hopefully be documented here someday. :-(
Until then, if you want more details I suppose you could read about computeInfill() in the AllSTLsToBuild file: