The GNU project has developed hundreds of software programs. Everything from system kernels to shells to desktop environments. They’ve created almost everything necessary to assemble a complete operating system: boot loaders, dozens of libraries (including the granddaddy of them all GLIBC), and scads of basic system tools and utilities. They’ve written language compilers and interpreters, as well as many other development tools of the highest quality. GNU currently has about 400 actively maintained quality software packages. You can get them from the GNU Project’s pages and other related websites.