A while ago, I had some interaction with the people at PCTeX. They let me have a copy of MathTime Lite for testing, which was very good of them. I now see that they’ve extended this to the wider world: MathTime Lite is now available for free. I’m sure there is good commercial sense to this decision (you still have to pay for the Pro version), but for people who want maths fonts beyond Computer Modern it’s certainly worth knowing.