This guide gives you pointers in making the transition from TTD to OpenTTD. Once OpenTTD matures more, this guide will grow. For now, here are the major differences that I<>ve seen.
* Being able to resize the window so that "full-screen" can also show so much more of the land
* Command Line switches to make things easier
* Generate Random Land in the scenario editor also builds small towns, forests, and industries
* A configuration screen that lets you turn on / off TTD Patch features
Some day, OpenTTD will contain the features of TTD Patch.