HPSG Diagrams

[Tom Hukari]

There is another math editor MathEq Expressionist Math Editor. You can
have a 30-day trial.  I am doing one now, with the Mac OS X version.
The interface isn't as seamless with Word as is MathType but  (unlike
MathType) it draws trees and (unlike the mac version of MathType)  it
has boxes for doing tags. MathType does not have a Mac OS X version yet.

http://livemath.com/products

Tom Hukari