Nothing's generated, all the files are hand-written. You can copy-paste an existing effect and just tweak the files to make new ones, e.g. changing the name and id and changing the shader code.
The shader language is WebGL's shading language. This is slightly different variant of GLSL that you traditionally get on desktop - it's based on GLSL ES, which is the mobile variant, plus the fact it's run in a browser and is often re-compiled behind the scenes for security reasons. This means desktop GLSL basically never copy-pastes and works - you'll need to carefully port it based on the limitations of WebGL shaders.
Ah, thank you. I was originally trying to see if I could get shurcooL's Motion Blur Demo (WebGL based, but I had thought GLSL was used in WebGL. Silly me ^^') to work in Construct. I wasn't gonna use it without permission, but I wanted to see how well it would work in-game. He wrote two separate scripts (One for fragment shading, one for vertex shading.), so I have no idea how I would get those two to work together, even though I don't know how to use the language anyways...
I'll certainty look into the language a bit more and see what kind of neat things I can create on my own, though. Thanks again!