jit.gl.light lets you add a light source to OpenGL.
Jitter Tutorial 35: Lighting and Fog is a good introduction to lighting in jitter. Although it uses the default light associated with jit.gl.render, not the jit.gl.light object, most of the information still applies to working with jit.gl.light.
jit.gl.light has a default light associated with it. Enabling any jit.gl.light object in a patcher disables the default light. Take a look at the light.basic.maxpat example included with max for a clear look at this behavior. You can find it under ./examples/jitter-examples/render/lights.materials/light.basic.maxpat
Lights can be used in a jit.gl.node objects sub-context.
You can use up to 8 lights in a scene at a time. Here's a nice example that shows both static and moving lights interacting with specular surfaces: Media: multi.lights.material.maxpat
Attenuation is a great and important way to enhance your lighting effects. This simple patch demonstrates how attenuation parameters cause the light to fall off over distance:
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