What is TTDPatch?
TTDPatch has originally been written by Josef Drexler. It is a most excellent patch that modifies Transport Tycoon Deluxe in a way that almost feels you are playing a completely new game. Have a look at the website at http://www.ttdpatch.net/ or at the TTDPatch Manual.
Is TTDPatch better than OpenTTD?
There are only so many things you can patch up in an old game without a total rewrite. While Josef Drexler and the many more recent developers made extraordinary improvements to the 'Patch', some things cannot be improved. OpenTTD tries to remedy this with an open source game that keeps the look and feel of the old game, but with a complete freedom over the game structure and features. A lot of projects have tried to make similar games, but we feel OpenTTD has come the closest and the furthest. Development is advancing quickly to filling up the gap with the great TTDPatch. Have a look at the feature comparison TTDPatch users here.
Which game shall I use then?
It is of course completely up to you. While TTDPatch only runs natively under DOS/Windows, it does run on Linux under Wine. More details can be found in the TTDPatch Manual. If you are in doubt, try out both of them. Currently the 'Patch', has an advantage in certain features such as new graphics, while OpenTTD has big maps and a working network. If you have chosen for TTDPatch, check back here regularly, since OpenTTD is continually improving, and supports more of TTDPatch's features with each build.