Let's say UAE is the only *free* and
Linux based Amiga emulator I know off :)
If you were willing to pay good bucks
you can get WinDOHs and/or QNX
software that supposedly outperforms
UAE... I believe Amithlon(AmigaXL) is
priced aroun 150 US$.
And there's AmigaForever, based on
WinUAE, but it comes with ROM images
and Kickstart, for about 60 US$.