system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is "hello world" always the first thing you write on computer programming applications?
gpt
In the past, the hardest thing about writing a new program wasn't the programming language.  It was understanding how your programming tools worked.  To use C as an example, in order to write your first program, you would need to:

1. Understand how your text editor worked, a non-trivial task on a text only, mouseless computer.
2. Understand how the file system worked, and how to save your program with the correct file extension to the correct location.
3. Understand how to run your compiler.  This was before graphical interfaces, so you couldn't just click a button.  You had to exit your text editor, type something like "cc -Wall hello.c -o hello", see if there were any syntax errors, and they pull up you text editor to fix them again.
4. Understand how to execute your program once you got it to compile.

That is a lot of things to figure out, "Hello, world!" is an exercise in getting them right.