From gnu.org:

The name “GNU” is a recursive acronym for “GNU's Not Unix!”

The GNU Project was launched in 1984 to develop the GNU operating system, a complete Unix-like operating system which is free software—software which respects your freedom.

Unix-like operating systems are built from a software collection of applications, libraries, and developer tools—plus a program to allocate resources and talk to the hardware, known as a kernel...

Here you can find a list of pages for programs and utilities from the GNU project.

See GNU Project for more details about this project.