#### Pros and Cons

Any command shell has characteristic capabilities and limitations, and there is often a love/hate relationship between expert users and the shells of their favorite command-driven software. In the case of the NeXtMidas, having several different shell modes of operation helps to silence critics; however, numerous operating "features" derive from the design and implementation of the NeXtMidas shell. This is true whether or not the user explicitly "enters" the NeXtMidas shell before issuing commands because that shell manages the execution of both interactive and one-shot commands.

One of the best features of the NeXtMidas shell is that you don't have to be in the shell to use it. When you type `nmstart` at your operating system prompt, NeXtMidas is set up. Now you can send commands to NeXtMidas right from the operating prompt with one-shot commands.

To work in the NeXtMidas shell, type `nm.` When you want to perform an operating system command, just type the O/S command at the NeXtMidas prompt as you would at your normal O/S prompt. If the first word of the command is not in the NeXtMidas dictionary, the command passes to the operating system beneath. If there is a NeXtMidas command with the same name as an O/S command, but you want to use the O/S version, just precede it with a dollar sign ($). In other words, type `$help` after the NeXtMidas prompt (`nM>`) to access the `help` of the operating system.

There is almost no reason to jump in and out of the NeXtMidas shell to work between NeXtMidas and the operating system.