While modding, I sometimes I find myself in a ridiculous situation where I have three or even four instances of Minecraft running on my computer at the same time. Using the Minecraft Coder Pack (MCP), I am able to conjure up a fresh instance of Minecraft with the click of a button. I can choose the username associated with the instance or have the program assign a random player name.
In fact, I don’t even play logged in with a launcher anymore unless I want to connect to a server. My main world is tucked inside my development environment now. By tweaking lines of code in the editor and rebooting the game, I can change the mechanics of the game and test them in real time. Computers are marvelous! They possess an unlimited capacity to create. If it can be displayed on a screen, a computer can be made to conjure it.
Programming can be a headache, but the high of creating something and seeing users engage with it is fabulous!