Draft:U9

U9 is an esoteric programming language by User:AnalysisOfVariance in 2026. It is a hyper-extension of HQ9+.

Overview

The program starts out with one thread and halts when there are no more threads running.

Each thread has an unbounded signed integer accumulator, as in HQ9+.

Lone expressions' values are printed, as to maintain compatibility with HQ9+.

Primary expressions

Command	Name	Description
H	Hello, world!	Returns the string "Hello, world!"
Q	Quine	Returns a string containing the entire program's source code.
9	99 bottles of beer	Returns a string containing the lyrics to 99 bottles of beer. By default, it uses "1 bottle" and "No more bottles" and this last verse: No more bottles of beer on the wall, No more bottles of beer. Go to the store, buy some more, 99 bottles of beer on the wall.
+	Increment accumulator	Increments the unbounded accumulator belonging to this thread.
-	Decrement accumulator	Decrements the unbounded accumulator belonging to this thread.
4	Random Number Generator	Returns 4.
F	Fibonacci function	Returns the nth term of the Fibonacci sequence (starting at F0 = 0 and F1 = 1) where n is the value of this thread's accumulator. If the accumulator is negative, returns null.

Examples

Hello, world! program

H

Quine

Q

Non-cheating quine:

Hello, world!

99 bottles of beer

9

Increment the accumulator

+

XKCD Random Number

4