I just blogged about Mallard+TTML. And earlier I blogged about XML translations with ITS.

One of the nice features of ITS Tool is that it can merge ITS definitions from multiple sources. So when you embed TTML into Mallard, you don’t need to have a specific Mallard+TTML mode. Instead, the Mallard ITS definitions get applied, and the TTML ITS definitions get applied on top of them. I just added this ITS file to itstool git:

  <its:withinTextRule withinText="yes" selector="//tt:p//*"/>

This ensures that inline markup like tt:span doesn’t get split off with a placeholder into a separate translation unit. This one file applies the ITS definitions whether your TTML is embedded in Mallard, DocBook, XHTML, or any other format, or even if you have a standalone TTML file.