I know that iPhone uses OpenGL ES 2.0, but I don't know the version of the underlying language GLSL. Is it 1.3, 1.4, 2.0, or other?
Ok, I found it myself, thanks to the _____VERSION_____ predefined macro. The GLSL ES specification used is the 1.0, which is based on the GLSL version 1.20. The OpengGL ES 2.0 and GLSL ES 1.0 specifications are available for download at http://www.khronos.org/registry/gles/.
Angus Forbes
printf("GLSL Version = %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION));
printf("GL Version = %s\n", glGetString(GL_VERSION));
On IOS 5.1, this prints out:
GL Version = OpenGL ES 2.0 APPLE
GLSL Version = OpenGL ES GLSL ES 1.0
来源：https://stackoverflow.com/questions/3456669/what-version-of-glsl-is-used-in-the-iphones