The router began as a port of FreeRouting and has grown its own engine
(negotiated congestion, tree nets, exact checks, axis escapes), and
'freeroute' was one letter from the project it no longer follows. The
package, module and command are now rpmroute; the freeroute command stays
as an alias, and the RPMROUTE / RPMROUTE_ORACLE_JAVA variables fall back
to the old FREEROUTE names. Version 2026.10.07. Routing is unchanged: a
PCBench board routes to a byte-identical session either way.
Ports the foundational board classes: Unit (mil/inch/mm/um with
micrometer scaling), Layer/LayerStructure (the layer stack with name and
signal-layer lookups), CoordinateTransform (DSN<->board scaling by the
resolution), Net/Nets (connectivity keyed by (name, subnet) and a board-
unique net number), and ClearanceMatrix (class x class spacing with a
reserved null class and a default class).
The per-layer axis of ClearanceMatrix is simplified to a single value per
class pair (DSN default clearance rules are layer-independent for the
boards we build); the router phase can add the layer dimension.
Unit-tested: unit scaling/parsing, layer lookups, transform round-trip,
net registration/lookup, and clearance default/append/symmetry.
rsp2k