Re: [filters] Shading language recommendation

It would perhaps be clearer if you answered my questions from earlier.
 I'll reproduce them here:

You've said that we should allow for expansion, so that future shader
languages can be supported.  Sure, that's reasonable.  But that has
nothing to do with what languages we require to be supported in the
beginning.  What is *wrong* with requiring GLSL as a supported
language, but allowing extensions such that you can expose additional
languages?

In a previous response email to Dirk, where you
repeatedly stressed the importance of developer choice in the matter,
but never actually argued for why "1 required option, + additional
choices" was bad.  Can you elaborate?  More importantly, can you
explain why that is worse for developers than "you have to write all
your shaders twice - once for IE and once for everyone else"?

~TJ