How many, what on earth we need libs for users?

How many, what on earth we need libs for using examples?

Reference to examples on the books, articles or papers, we find there are too different libs in using, so does extension lib…
Where can we find a complete lib for all these uses? or get a complete explain for beginners use, for example,
glut has been ceased, and freeglut in place, glew by simple glee, and gltools is also occuring in some examples.
where shall we get all of them in one doc, such as sdk to install in order to reduce searching time.