[mhx]

I imagine it would be possible for it not support G3's, although I haven't heard anything to that effect (and this laptop is a G3 which is still in heavy use so it's not going to be too happy if it's not supported :-)

[quidnunc]

Even if your G3 doesn't support Tiger, you can continue to use your present OS.

My wife still uses Jaguar on her G3 and she's satisfied with it.