www.makemkv.com

I have MANY .toast image files that I generated over the last 10 years using Roxio Toast. I saved them to use as backups for burning Bluray disks on my Mac. Now I want to make mkv files directly from some of these .toast image files without burning a disk first. Is this possible? (I don't see the answer online or in this forum)

MakeMKV doesn't support .toast files. You could try extracting the contents of the .toast file to get the original contents of the discs, but even then MakeMKV may not be able to open them. MakeMKV generally requires the original disc, or the folder generated by its own backup function.

Interesting. I was unaware of this image format. Apparently this is the whole disc image with some metadata.
As was said earlier, MakeMKV does not support this image format directly. You have to convert .toast to ISO (with disk utility for example)

Regarding the image contents:
- if the source is DVD, you would be able to open them with MakeMKV.
- if the source is Blu-ray, then it is more complicated.
If you made these ISO on a drive without bus encryption, you would be able to open them with MakeMKV, but you might need to download the key files.
If these ISO were made with a recent bus-encryption enabled drive, then no software would open these images, regardless of the format - toast or ISO. But, if you have access to the original disc AND the dive you've made the image with, then you can extract the required keydata from each disc to make it usable with MakeMKV. This is a fast, but manual process. You would have to insert each disc to the drive and produce a few files.

p.s. I'm getting intrigued, I'll try to see if direct .toast support can be added...