PDF backend

OK. Was it just that you don't want to require mpl users to

    > install fonttools, or were there other problems with it?

One problem was that it was large compared to mpl at the time, and mpl
was pure python. So it complicated the distribution to have a large
piece of extension code that wasn't quite as ubiquitous as numpy. Of
course now mpl is much larger and has it's own extension code headaches.

    > Does anyone here have experience with subsetting TrueType
    > fonts (or Type 1 or OpenType, for that matter)? One pretty
    > frequent complaint is that the eps files produced by
    > matplotlib can be huge because they include the full
    > font. Nowadays some popular fonts include characters for
    > Greek, Cyrillic, Hebrew, Arabic, and possibly even Chinese,
    > Japanese, and Korean, so a font can be several megabytes
    > large.

I would love for someone how to figure out how to extract and embed
just the needed glyphs rather than dump the whole file in. I'm 99%
sure this is possible, it just takes some dedication.