Yep. That's something good. Unlike Steam that released old glories without much of support (Commandos and Fallout come to mind), GOG wrap these gems in a DOSBOX shell, tweaked for best result and they even have a full team of skilled individuals that, in case of trouble follow you step by step and fix your issues (within the game...
).
In case the game still is unplayable there's a 30 days warranty of full money reimbursement.
They're pretty frakking awesome.