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.
Two connections of a net can share a via. The grid kept one owner per via
cell next to the claim list, and the search and rip-up read only that owner:
a route of another net through the via ripped the first user and left the
second's via under the new trace. The exact check then threw one of them
out. The search and rip-up now read the claim list, and the single owner is
gone.
The exact check also tested a via against the outline as its square box,
whose corner reaches past a 45-degree chamfer where the round via does not.
The grid keeps the via's centre its radius plus the edge clearance from the
outline, as KiCad measures it; the exact check now does the same.
kitspace_minisumo_v3 seed 4: 4 rejected connections to 0, 11 failed to 7.
Over 8 net orders it left 25 to 30 fewer connections unrouted on the
dense sense boards and 16 to 18 fewer on two PCBench boards, and was
never clearly worse. KiCad DRC on the sense harness: 41 opens to 28.
The connections a rip-up route crosses are rerouted at once in free
space. If that leaves fewer connections routed than before, the new
route comes out and every displaced connection goes back on its old
path, with its rip count as it was. Even trades are kept.
rsp2k