Underload

Underload is a language created by ais523 in 2006. This details how it is implemented here.

Memory

A stack of strings.

Instructions are single characters, and are executed from left to right.

Command	Effect
`(aaaa)`	Push string contained between the outermost `(` and `)` to the stack, jump past the latter
`!`	Pop top of the stack and discard it
`:`	Push a copy of the top of the stack
`~`	Swap the top two elements of the stack
`*`	Pop top of the stack and concatenate it to the end of the new top element
`a`	Surround top of the stack in `()`
`^`	Pop top of the stack and execute it as Underload code

Command	Effect
`S`	Pop top of the stack and print it