05AB1E is a concise, stack-based golfing language.
You can use Try It Online! to run these programs.
"Hello, World!
The expected Hello, World! program is "Hello, World!" (pushes the string Hello, World! to the stack and then implicitly outputs it). However, the trailing quote is optional, allowing for a more concise program "Hello, World!.
It seems that somebody has found a more concise program than me, but it is not in any way readable.
GN*
This is a pretty simple program that outputs the factorial of the input.
- The input is pushed to the stack
G - Loop the code until } until N is the first element in the stack (starting at 1), for(N = 1, N <= input, N++)
N - N is the counter variable for the loop, this pushes it to the stack
* - Sum the top 2 elements of the stack and push it to the stack
- } is implied (the end of the loop)