The HTML documentation contains both tutorials, guides for different topics and an API reference.
The FAQ answers many commonly asked questions about the design, implementation and use of GLFW.
GLFW is under the zlib/libpng license, which permits modification, distribution and use in closed source software.
Below is a short example of setting up a window and OpenGL context with GLFW. There are many more functions than those used here. For a quick introduction to GLFW, see Getting started in the HTML documentation.