Is UltaEdit for Mac compatible with M1 Macs? Can it run in Big Sur? When is the next UltaEdit for MacOs release going to be, I noticed the current release is a year old. 

This is a user based forum so no one here can help you with your question regarding an M1 Mac.  You will need to contact IDM support regarding their plans for this.  As for the next release of UE for the Mac, that's coming this northern summer according to an update notice I received from IDM

Cheers,
Frank

Thanks that's useful. I will wait till then to buy.

Theoretically, UltraEdit for Mac should run on an Apple M1 machine using the Rosetta 2 application to translate the Intel code into M1 code.  However, I recently updated to 20.00.0.18 and the app crashes as soon as it starts.  I then upgraded to 21.00.0.12.  It runs as expected.

Thanks, that's what I expected but wanted to confirm it runs under Rosetta 2. 

Hi, I am a long time customer (sine 2010) of the mac version with unlimited upgrades. I just downloaded the latest mac version of UltraEdit and I noticed it is still an intel only app. There is not many years left of apple support for intel based mac's. Will there be a recompiled version as a universal binary for both intel and apple silicon?

FWIW I got the following, very non-comittal response when asking support
"We do plan to support M1 natively. A Mac release is planned for later in the summer, and at that time, we will evaluate what is required. This isn't a guarantee that we will have a native M1 version by the summer, but it is one of our priorities for Mac."

To be honest, although a great and frequently updated app on windows, I wouldn't bother on Mac. It's clear from the lack of updates that it's not their priority and frankly not having an M1 update out by now is awful.

Shame.

That's a shame indeed. I've been using UltraEdit for over a decade and I love it still, also on Mac. But if they don't even bother to update it to work on M1 I guess it's time to look elsewhere.
But what are good Mac/M1 alternatives?