Just wanted to let you know that I sent an email yesterday to the Pango mailing list, asking about the possibilities of expanding the fonts Pango can represent beyond what CSS can represent. Haven't heard back yet, and have no idea if they will tell me this is technically impossible or philosophically undesirable. However, if I get good news, this may mean I can help expand it and then support more fonts in Inkscape as a result. Will keep you updated.

Gail