Feature difference b/w xemacs and gnu-emacs ?

I dont see the tabbed frames working on the xemacs 21.5 version. Do you know why, as this is the listed feature difference b/w xemacs and gnu-emacs ? Thanks, - Kiran K. Patel CEM / Vz LR Team. Verizon Data Services, 1-813-978-2207 Kiran.Patel(a)verizon.com Florida, USA