the POET fabrication processes won't necessarily have to be re-written every time, moreso they must be "re-expressed" in the format ("language") that the particular design rule checking (DRC) software requires. still hairy, but not like starting from scratch.
that POET is this far along is pretty impressive. it's a guidepost that says we're out of the prototype woods and onto the edge of serious pre-production validation.
this might be worthwhile
http://en.wikipedia.org/wiki/Design_rule_checking
and a pretty good primer...
http://www.jontse.com/courses/files/cornell/ece4740/SemiconductorFabrication.pdf
and for any uber geeks, here's a site to go lose yourself in...
http://semimd.com
GLTA,
R.
