GLSL Status and Capability (FBOs, UBOs)

I have been seeking answers to the following related questions, but cannot
find them in the forum archive:

(1) What is the GLSL support version? I ask because I'd like to explore use
of the Uniform Buffer Object, which is supported in OpenGL 3.1/GLSL 1.4,
and perhaps the Geometry Shader of GLSL 1.5. UBOs, FBOs would be potentially
useful in captured delayed textures and gathering statistics on texture
values (all within the GPU).

(2) Are read/write buffers of the UBO and FBO sort surfaced in jit.gl.pix ? I've
seen some references to FBO but only in terms of errors encountered. My question
is more related to whether one can read/write to this secondary memory area. As
long as this sort of buffer is supported in shader development (e.g. .jxs) then
this would be useful even if not surfaced to the language in jit.gl.pix. In reviewing
the jit.pix and jit.gl.pix documentation, I couldn't see anything like that.

Thanks.