App::Cpan

App::Cpan is an excellent Perl module that allows for easy interaction with CPAN via a command interface. It is important to note that this is not a shell, but rather an interface that you can use to access CPAN's functionality. Currently, App::Cpan uses CPAN.pm to execute commands, however, it is not a one-time shot command runner for CPAN.pm.

The SYNOPSIS of App::Cpan is very useful for those who are new to the program. It highlights different ways to use the module, starting with using arguments and without any switches to install specific modules. On the other hand, using switches with module names installs the modules with extra behavior, while using just the dot installs from the distribution in the current directory.

Moreover, App::Cpan is also capable of starting the CPAN.pm shell, a useful feature for those who want to explore and use CPAN's shell functionality. Finally, the use of switches without arguments is an excellent way to access the helpful additional options provided by the module, such as -ahrvACDLO.

In conclusion, if you want an easy-to-use interface to access CPAN.pm's functionality, App::Cpan is definitely a Perl module to consider. With its SYNOPSIS given, you'll find it very useful in terms of its capabilities and features.