Gloop
Gloop is an OpenGL interface for Crystal. It provides an object-oriented and “crystalized” interface for using OpenGL. Gloop is an acronym for Graphics Library Object Oriented Programming. This project is still in heavy development, but the most of the commonly used OpenGL functionality is implemented.
Similar to OpenGL, Gloop requires a context to be established before it can be used. The context can be provided by windowing systems such as GLFW and SDL. Espresso is a shard that natively works with Gloop that uses GLFW. The SDL shard by @ysbaddaden also works with Gloop to provide SDL bindings.