OpenTTD is an extremely popular open source game based on the series of novels written by Allen M Schoonover. It's basically a modification of the well known TTD (The Ticket To Ride) computer game. It's very similar to the one but has a lot of changes. For example, it doesn't have graphics but it does come with the scenery. The graphics are rather low quality and the sounds aren't of high quality either. But it still remains to be the best game ever developed for this genre.
OpenTTD is mainly a simulation game based on transportation. So like many other simulation games, it uses maps, roads and tracks in order to simulate different types of transportation. OpenTTD has a lot of options for controlling the map and other elements. In this way, you can choose the route you want to take and also the path you will follow in the game to reach the goal. As the game is modelled on the original, you can also find a lot of features like advanced routing system, terrain textures, buildings and airports, as well as the likes.
Downloading software to play this game is easy, especially if you use the Internet. You need to visit websites offering OpenTTD downloads. They usually offer different levels of free download to help players get started. After you've downloaded the game, you need to install it on your computer. There's usually no software needed except some basic Windows skills. OpenTTD will install itself automatically, so you don't have to spend time installing everything. If you want to enjoy the game faster, you should consider running the game from an external program or from a CD, rather than directly from the computer hard disk.