SCARM - Simple Computer Aided Railway Modeller
RailModeller - RailModeller is a new application for creating model railroad and slot car layouts.
TrainCad - Freeware Microsoft Windows program for designing model railroad layouts using standard tracks.
WinTrack - Track planing software
Empire Express - Empire Express: Model Railroad Design for Mac
AnyRail - AnyRail makes model railroad design so easy, it's fun!