Amithlon is a fast 68k Amiga emulator based on the UAE JIT engine; it runs on generic x86 hardware on top of a custom Linux kernel.
It runs a slightly modified AmigaOS 3.9 (68k) with Amiga RTG and RTA drivers that talk to the Linux kernel, allowing most system friendly AmigaOS 68k applications to be run. AmigaOS has access to the hardware directly as well. The emulation brings with it a speed penalty - the OS is not as responsive as it would be if it were running natively (like AROS does) however Amithlon is generally faster than a "classic" machine, given a vaguely modern PC, and far cheaper than a kitted-out Classic Amiga.
The Amithlon is also generally much faster than a typical hosted emulation (where the emulator runs in usual manner - executed by user from Windows, Linux, etc.). By means of direct hardware access, the Amithlon provides AmigaOS access to PCI devices. This means no actual graphics card or audio chip emulation is required. There are even 2D accelerated drivers for some video cards (ie. Matrox G400 - with DualHead support!). Other cards (such as ATi Radeons) run in VESA modes. There are also standard AHI drivers for SoundBlaster 128 and VIA AC'97 chips. In general, all PCI devices having an AmigaOS 68k driver work (USB OHCI, RTL8139 Ethernet, ...).
Amithlon works for system friendly applications, but due to the lack of Custom Chipset emulation most games and Demos will not run. AmigaOS applications can be compiled for Amithlon, in which case they directly use the host's processor, without emulation. This provides fast speeds for video decoders, Datatype?s etc. In reality almost no native software is available.
Amithlon was discontinued due to legal issues. The proposed successor to Amithlon, Umilator?, was never released.