To help the players various programs are being developed. Programs for GTA San Andreas are different. They could be, for example, trainers - programs designed to change the data in the game while using it. For example, with Trainer you can change the weather in the game, get any weapon or a make appear any vehicle and many other useful things in the game.
It can also be a program to edit the various game settings, for instance, using the Handling ED, you can change any options for any vehicle, such as handling, or weight of the vehicle.