I have several small groups of scripts and functions that go together to be a system. Others are more complex. Note that some scripts rely on access to functions (if any needed function isn't here, please let me know), and/or preference file(s) in ~/.prefs.

One small system is a group supporting interactive shell work. '
pu', 'po', 'ch', 'pw' and 'PW' implement a directory stack system with the current directory being displayed in the header of an 'xterm' window with another element 'xtitle'. These are suplemented by 'root', 'soot', and 'us' (become root using 'su', ditto using 'sudo', and suspending a 'root' or 'soot' session to return to the original user), which maintain the correct data in the header. 'us' can be conditionally defined in '.profile' to avoid it freezing a login shell.