May I start by thanking you for your hard work in submitting the patch for Knuth's Line breaking algorithm.
I'm just starting to look at your patch now. First thing that strikes me, and this was pointed out to me before I became a committer. Please try to avoid commenting out large chunks of code. If the code is no longer needed please delete it. If we need to go back to the old code, we can always get the previous versions from CVS.
Second thing, are you just ignoring word spacing and letter spacing at the moment? I think one of the other FOP Dev's hit the problem of "how do we tell if property was specified or is it just the default" before? Hopefully they will speak up with a work around. If we do go without the letter spacing property, then they really ought to stay as NotYetImplemented in the FOPropertyMapping and just put come comments into the code to explain why it cant be implemented ATM.
I'll comment again once Ive done some testing. Thanks,