Hello World Without Libc: A Deep Dive into How Programs Really Work

Introduction Most programmers start with a simple “Hello World” program like this: #include <stdio.h> int main(void) { printf("hello world\n"); return 0; } But have you ever wondered what really happens under the hood? What is printf doing? Where does main come from? What happens before main is called? How does the program actually communicate with the operating system to display text on the screen? In this article, we’re going to build a “Hello World” program in C that requires no standard library (no libc)....

May 11, 2026 · 32 min