glslbin is a fragment shader sandbox similar to ShaderToy or GLSL Sandbox. It's still a work in progress, so expect more to come soon.
It adds support for glslify, a GLSL module system which allows you to easily pull in shared code snippets from npm.
These modules are all hosted as part of the stack.gl project: you can find a full list of packages in the "Shader Components" section here. Enjoy!