Why todo.txt? Countless software applications and web sites were built to manage your to do list. But if you're comfortable at the command line and you don't want to depend on someone else's data format or someone else's server, there's an age-old method that's perfect for tracking your stuff: plain text.
Keep on top of all your tasks and projects in a simple file called todo.txt. With a few helper scripts, you can slice, dice, sort, distribute, pipe and munge your lists any way you please. As it should be. Plain-simple. :)