So will it be possible to use this new ScummVM with GOG's version of Myst? Or does something have to be converted first?

It should just use the regular files. Normally you just provide the data files and assets and the SCUMM does the rest.

Yay!
I might finally be able to get around to my original boxed version of Myst without mucking about in ancient versions of Quicktime.

Before I remember why I never really cared for Myst....

If the GOG version has these files, it's ready to go: http://wiki.scummvm.org/index.php/Datafiles#Myst

Thanks for the info!

While the support is experimental and only present in the daily builds of ScummVM? No, they shouldn't.

Good news for GOG, SVM compatibility essentially means Myst will have perfect compatibility for Win/Mac/Linux for the indefinite future, while the old Windows version will probably eventually get broken by new Windows versions.

This is great news. Its good to see ScummVM bringing these old classics to the modern day. We are very lucky nowadays with DosBox, Scumvm and the various emulators for free.

This isn't strictly true. While a good portion of DOS software does work under DosBox, there still is titles that it's not fully compatible with. It still runs probably around 90% of all titles, but even for the newest builds there's titles that won't run at all.

i keep forgetting that scum vm can play discworld 2

Out of curiosity, are these listed somewhere? EDIT: Ah ok, maybe this:

http://www.dosbox.com/comp_list.php?letter=broken

I generally like DOSBox as I've had even better success rate running games on it than on my old MS-DOS retro-PC. Go figure, an emulator is more compatible with old games than a real MS-DOS PC...

EDIT2: Interesting that DOSBox "broken games" list, it includes games that I think even GOG has? Like:

Eye of the Beholder 3
Red Baron
Ishar 2
Tie Fighter

Aren't the GOG versions using DOSBox, and how did GOG get them working then?

Good point, ScummVM going beyond mere DOS games... Let's hope then ScummVM will add as many early Windows games as possible to their support list. :)

Goat offerings and demonic magic, nothing really strange or unusual.

Supported on DosBox 0.73, broken on 0.74

Supported on DosBox 0.73, broken on 0.74

Supported on DosBox 0.73, broken on 0.74

Supported on DosBox 0.73, broken on 0.74

Not to mention that I'm not sure when the broken list was last updated, since comments on all 4 games indicate that some people got those to work with 0.74.

I just gave a try to Myst in ScummVM on GNU/Linux, and so far it seems to run great.
It is also much less resource-hungry than running Myst with WINE.

ScummVM built from 2016-03-28 git in a Debian Jessie i386 chroot
Myst data extracted from GOG installer with innoextract

I still need to give a try to the fortress rotation in the Mechanical Age, that point being where older ScummVM builds did fail.