pwgen

1. Focuses on memorable passwords, and restricts itself to fewer ASCII characters than rpg.

2. Makes no attempt to preserve entropy; waste of entropy is potentially unbounded. This is a performance concern when reading from /dev/random, and a security concern when reading from /dev/urandom.

3. Has large source code spread across multiple files. Good for reusability of components, not so good for auditability and security.

4. Requires Perl and sed.