Lately I've read a lot about Panther problems. Many developers deliver "Panther ready/compatible/compliant" versions. So do we with SubEthaEdit 1.1.5.
I'd like to comment on the subject because some of the conclusions you could draw because of this fact.
It turned out that most of the crashes we got with SubEthaEdit were due to bad things we did, that jaguar tolerated. E.g. in one place we did some memory-mismanagement. We made a chain of callbacks, which at the top level released the object, that initiated the chain. As we found this out we were astonished why this didn't crash on Jaguar.
After having dealt with many other Panther related issues now my impression is the following:
Panther is not at all particulary buggy. Panther is more streamlined, optimized and strict. If you programmed things not according to documentation and specification, but according to you trial and error tests, then the probability of problems on panther with your application is quite high. But of course this is not a good programming style.
The one thing you can accuse Apple of, is not telling their developers that Panther will be more strict. That would have helped. In our case we would have nailed down the crash earlier (because we would have known it is not due to the beta of Panther).
I personally am very pleased about the development speed and quality that Mac OS X is keeping up, if not even increasing. IMHO as a user and developer I'm looking forward to a very bright future.