Nailgun is a client, protocol, and server for running Java programs from the command line without incurring the JVM startup overhead. Programs run in the server (which is implemented in Java), and are triggered by the client (written in C), which handles all I/O.
Here are some really useful command line shortcuts that I found on a forum awhile back but don't remember now: F1 Repeats the letters of the last command line, one by one F2 Displays a dialog asking user to "enter the char to copy up to" of the last command line F3 Repeats the last command line F4 Displays a dialog asking user to "enter the char to delete up to" of the last command line F5 Goes back one command line F6 Enters the traditional CTRL+Z (^z) F7 Displays a menu with the command line history F8 Cycles back through previous command lines (beginning with most recent) F9 Displays a dialog asking user to enter a command number, where 0 is for first command line entered