There is not a lot for the Mac out there. There is one scalextric editor for Mac OS X. Its called Trackdesigner..i think the current version is 1.2. Dont have a link at the moment but do a search on google.
For mac OS 9 there is Railmodeller (or something like that)...its really for modeltrains but have different libraries also for Scalextric, Ninco etc.
Railmodeller runs in OS9 and OSX, works for every type of slot car track and is simply fantastic.
Railmodeller is extremely Mac-like. It is drag and drop, can calculate a parts list with track piece numbers, a lap length, and even a price list. You can use different colors for different track pieces and export your design as a graphic file for posting on the web. You can also create geometric shapes, lines, and text for planning scenery or planning how to build support sections for the part of your layout that is elevated. Track pieces "snap" into place and you can make very accurate measurements and also control the view size of your layout.
Railmodeller's author, Jan Barnholt, speaks English and German and is very helpful and open to suggestions. Railmodeller uses track libraries for different track systems, whether they are slot car track or railroad track. It comes with a library for Scalextric Sport (the track I use) and libraries for many other slot track systems. It also has an editor so you can create your own library that is very, very easy to use.
Railmodeler's homepage is http://www.railmodeller.de/, check it out, for my money it is the best Mac layout designer available. I am not connected with Jan or Railmodeller financially.
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