Posted by Thomas Phinney
One of the things we had kind of left behind in the migration to OpenType was compatibility. More specifically, we renamed all our fonts so that people could use the OpenType versions alongside the old Type 1 versions. Making them deliberately not compatible then freed us to extend kerning, expand the character set a bit, and make other fixes and changes of varying degrees.
But still, people want to know which OpenType fonts match which Type 1 fonts, and what will happen if they take existing documents and replace the old fonts with the new ones (which of course means changing style definitions or using search and replace). Will they get reflow, and how much? First, we did documents about mapping from Type 1 (including multiple master) fonts to OpenType: a short HTML doc for MM to OpenType, and a huge PDF for regular Type 1 to OpenType.
Then, just a couple of weeks ago I finished a long and complicated migration FAQ on compatibility, reflow, and what exactly we changed. I’ve been working on this on and off for months, just as a background task, adding more things as I thought of them. It’s still not perfect – for example, I left out explanations about pi fonts, or at least linking to the pi font readme, which I should have done.
So, I expect I will continue to evolve the migation/compatibility FAQ for a year or two, and I welcome feedback for future revisions. Feel free to post your comments here.
(BTW, everything is linked from our main OpenType page.)