Stream based template modifiers

[mitar]

What people think about adding some pipelines to how templates are rendered? I really like how Genshi supports stacking something like XSLT on top of each other to transform the output.

For me markup streams are an interesting idea where you can see HTML as a stream of markup you can then modify. See example in the templating library Genshi. The question is though how much that works with reactive rendering. This streams were mostly used only for static rendering. But in theory reactive they should make things work even better. But none of current libraries really support that.