If you want to run lots of assembly programs that you can download off of sites like this one, cemetech.net, or ticalc.org, Doors CS 7 is the way to go, for now. It's probably the best shell out there currently. The thing about MirageOS and Doors CS is that it allows assembly programmers to have a library of functions that they can use. This is also why some MirageOS programs don't work from the home screen, and stuff like that. However, Doors CS 7 has full MirageOS/ION support, along with xLib and Celtic and a whole bunch of it's own functions.