TrainPlayer/TrackLayer for Mac OS X is a new application developed natively on the Mac using Xcode. TrainPlayer simulates operation of a model railroad layout, with support for multiple trains, control panel, coupling/uncoupling, yard mode, zoom, and other features. TrackLayer is an add-on module for drawing track, curves, switches, and turntables. Layouts can be assembled from scratch or traced over images or layouts from other programs.