63

63 is a joke esolang by user:raiseafloppafan7741 in 2026. It was made with the goal of severely pissing off Esofish implementors with a possible and easy but very tedious challenge to prevent Esofish's realization for a few more weeks. However, 289 makes 63 trivial and so 63 only matters for 8-bit Esofuck implementors now.

Overview

There are two unsigned unbounded integer accumulators. They are both initialized to zero at the start of the program. If they are decremented below zero, they stay at zero.

Command	Description
I	Increments the first accumulator.
D	Decrements the first accumulator.
S	Squares the first accumulator.
R	Takes the rounded-down square root of the first accumulator.
i	Increments the second accumulator.
d	Decrements the second accumulator.
s	Squares the second accumulator.
r	Takes the rounded-down square root of the second accumulator.
X	Takes the remaining lines of the program and interprets it as a program in the first accumulator person's second accumulator-th programming/markup language, not just an esolang. Trying to run a language index which does not exist is undefined behavior.

This is the list of esolangers to be indexed by the first accumulator. Note that this list should start from zero.

1. User:Aadenboy
2. User:ais523
3. User:Areallycoolusername
4. User:Assembly
5. User:Blashyrkh
6. User:Chris Pressey
7. User:ChuckEsoteric08
8. User:Cleverxia
9. User:Corbin
10. User:Cordership
11. User:CreeperBomb
12. User:Dragoneater67
13. User:Hakerh400
14. User:Hammy
15. User:Hotcrystal0
16. User:Keymaker
17. User:MarkFan8901
18. User:Miui
19. User:None1
20. User:PrySigneToFry
21. User:Ractangle
22. user:raiseafloppafan7741
23. User:RikoMamaBala
24. User:RocketRace
25. User:Salpynx
26. User:Spira.
27. User:Timwi
28. User:Xi-816
29. User:Yayimhere

Computational class

The esolangers in the list above have all made many Turing-complete languages such as Iterate by User:Aadenboy, many of User:ais523's languages and computational models, Crazy J by User:Blashyrkh, and more. Therefore, 63 is at least as powerful as a Turing machine.

However, some of these esolangers such as User:None1 have made uncomputable esolangs such as UCL (Uncomputable Constant Language) which makes 63 uncomputable.

Examples

Hello, world!

user:raiseafloppafan7741 (narcissist /j), Nonstraightforward

IISSIIIIIIX
~/dev/stdout/write/ln("Hello, world!");

Cat program

User:Aadenboy, Braingrate

X
;[.;]

Quine

User:Assembly, Rat of choice

IIIX
"~a:$\nXIII":a~

Truth-machine

User:Assembly, Rat of choice

IIIX
ℕ^11:a*^3→^1.a←0.

See also

• Esofish
• Esofuck
• 6
• 59
• 93
• 289
• -2