T & L stands for Transform and Lighting, it's specifically means your video
card must have this capability built into the chipset of the card. Think ATI
or nVidia video cards as "the" choices. I know the earliest ATI card with it
is the Radeon 64 DDR VIVO (7200) because I have one. I don't know what card
is the first to have it on the nVidia side, my TI4800SE certainly does.
Nowadays a "newer" neccessity has reared it's head for some games. The need
to also have a "Shading" engine incorporated into the card. My older ATI
card doesn't, my newer nVidia does. Keep this in mind when/if purchasing a
new video card.