I want to use Mindwrite on new Macs. Is there a fix that will allow it to run on them? It is the best outliner I have ever used.

I couldn't agree with you more that MindWrite was the best! Did you ever get any answer as to whether it's possible to use it on current Macs? My understanding is that MW was written in 16 bit code. Current Mac operating systems work in 32 bit mode. Thus, the problem. I have seriously thought about hiring someone who knew how to transform MW from 16 to 32 bit to do it. I am assuming that it would then run OK, but perhaps it's more complicated. If there were enough of us, I would definitely contribute to have this done.

What do you think?

I figured out a way (for now) to use MindWrite! But you need to have an old Mac machine that can run MindWrite (such as mine which is running OS 7.1--on a Mac Ci). You can work on the old machine, use the built-in Mindwrite filters to convert the file to Word 3.0. Copy the file and transfer to your new machine, running OS 9, and open up in latest Word version (I am using 5.1). Word 5.1 can open up your Word 3.0 file by converting it with its built-in filters.
For the other direction, you can compose material in Word 5.1, but save it as a simple text file. Copy the file and transfer to the old Mac. MindWrite can open the file in text format, so you can add your raw material to what you're working on. It's awkward. But still doable if you need MindWrite for organizational purposes.