Tau

τ or tau is a text and stack based programing language made in snap programing language

You have the commands:
[ - Closed by ], push text to stack, use \ to escape characters
⁅ - Closed by ⁆, like [], but push applying rules to the text
# - Pop a number an convert it to unary
$ - Pop a unary and convert it to decimal
+ - Pop two strings and concatenate
- - Pop two strings, A and B, push the length of A - B
* - Pop two strings, A and B, push a string containing length of A copies of B
/ - Pop two strings, A and B, push ceiling of length A / lB
λ - Pop a regex and a string, A and B, match every A in B
| - Pop a regex and two strings, A, B and C, replace every A with B in C
Γ - Pop a regex and a string, A and B, test if B contains A in it, if true, push Y, else, push N
π - Pop a regex and a string, A and B, create a rule
( - Read input
= - Pop and push it reversed
) - Pop and print
: - Pop two items, A and B, Push Y if A = B, else, push N
; - Pop two items, A and B, Push Y if A != B, else, push N
> - Pop two items, A and B, Push Y if A > B, else, push N
< - Pop two items, A and B, Push Y if A < B, else, push N
α - Pop two strings, A and B, do an and gate
Δ - Pop and do a not gate
ε - Pop two strings, A and B, do an or gate
\ - Pop two strings, A and B, run A if B is Y
{ - Pop and run until Last item of stack is N
§ - Switch Stack1 with Stack2, vice-verve
? - Pop and push from Stack1 to Stack2
¿ - Dequeue and push from Stack1 to Stack2
! - Pop and push from Stack2 to Stack1
¡ - Dequeue and push from Stack2 to Stack1
^ - Pop and push inclosed in brackets
↮ - Pop and push inclosed in ⁅⁆
& - Run as tau code
, - Pop and do nothing(drop)
. - Duplicate
¢ - Switch with stack last and stack penultimate
% - Pop two strings, A and B, push length of A mod length B
¹ - Pop and push the length
² - Push the length of Stack
³ - Pop and push a random number from 0 to the popped value
1-9 - Pop, multiply by 10 and add the number
´ - Push a null
⫯ - Pop and get the head of the string
⫰ - Pop ang get the tail of the string
σ - Pop and push ascii for the number, separate chars with spaces
θ - Reverse of σ
° - Pop and remove rule
⨀ - Pop two strings, A and B, run A, B times
ϱ - Pop a string, A and push item length of A (0 is first item)
ϸ - Pop a string, A and push item length of A (0 is last item)
ϼ - Pop a string, A and push first item with the value A
⨜ - Reverse stack
⨇ - Pop a string, A and move item A to the top of the stack
⨈ - Pop a string, A and B, move item B to position A in the stack
⩤ - Pop two items, A and B, Push Y if A <= B, else, push N
⩥ - Pop two items, A and B, Push Y if A => B, else, push N

Hello, World!:

ß)

Truth-machine:

(´0;[1)]{0)<

deadfish:

[-program here-]
[acc]´0π
[i][[acc\]⁅acc⁆#[*\]+$π]¿?|
[d][[acc\]⁅acc⁆#[*\]-$π]¿?|
[s][[acc\]⁅acc⁆#.*$π]¿?|
[o][⁅acc⁆)]¿?|&[acc]°

Compiler: https://github.com/dmiz-1/tau