The icewindale thing would be spine of the world. I believe it was made by the same team that made Tortured Souls, and Hlidskalf (sp?) later converted it to weidu format. If I'm not mistaken the spine of the world allows you to play IWD on the BG2 engine, I don't know what the differences in the egines are as I have never played IWD. If you want to download it there is a link to all of Hild's refurbished mods in the sticky thread "Comprehensive BG2 Mod list", or there might be information over at
www.teambg.com , but I'm not 100% sure.