GlslViewer is a flexible console-base OpenGL Sandbox to display 2D/3D GLSL shaders without the need of an UI. You can definitely make your own UI or wrapper using the Python Module (include) or any other tool that communicates back/forth with glslViewer thought the standard POSIX console In/Out or OSC.
GlslCanvas is JavaScript Library that helps you easily load GLSL Fragment and Vertex Shaders into an HTML canvas. I have used this in my Book of Shaders and glslEditor.