Simply Horses opens the player to a new mode of play, both advantageous and detrimental. With this mod, one can catch his own horse, break it, and use it in one of three ways- to race around the world and push the borders of their domain, to trample over enemies, or to make day-to-day work and travel a bit more doable. There are also new tools to help you, from simple storage carts to homely wagons.
For MAC: If you have issues with SparrowAPI.class or SimplyID.class, move both files into minecraft.jar
For Minecraft 1.5.2
For Minecraft 1.5.1
For Minecraft 1.4.7