fo processor features

Hello all,

I'm working with the Object Management Group (http://omg.org/) to
establish the feasibility to support DocBook as a source format for OMG
/ ISO specifications.
It appears DocBook itself is very well suited to write specifications,
however the quality of available FO processors is still rather limited.
Two particular features I'm interested in right now are MathML support
and fo:float (as a way to format annotations).

The two formatters I have immediate access to either don't support
fo:float (apache's fop) or don't support mathml (xep).

Thus I wonder: can anyone recommend a good fo processor with good
coverage as far as support for the above (and other standard-) features
is concerned ? Or even better: is there a publicly available feature
matrix comparing the available solutions ?

Many thanks,
        Stefan


-- 

      ...ich hab' noch einen Koffer in Berlin...