They are using the Neverwinter Nights engine. I've never played Neverwinter Nights, but I'd check it out if they had a Dark Sun setting.
If you have the skills and time to help, they are always searching for more assistance. Thank you.
You can contact them on Twitter at ttps://twitter.com/NwnDarkSun @NwnDarkSun
The following are some screen shots of some of what they have accomplished.