I am guessing it wont take long for Apple’s infamous legal department to cease and decist this cool PPC emulator, so download it while you can.

PearPC emulates a G3 CPU on an intel complete with expirmental X86 JIT support.

Features

• License: GPL
• Programming language: C++, C and (on x86 platforms) assembler
• Supported platforms: POSIX-X11 (Linux, …), Win32
  
  The following operating systems were tested and run (to some extend) under PearPC:

• Mandrake Linux 9.1 for PPC: Runs very well
• Darwin for PPC: Runs well
• Mac OS X 10.3: Runs well with some caveats
• OpenBSD for PPC: Crashes while booting (accesses PCI in an unsupported way)
• NetBSD for PPC: Crashes while booting
  
  PearPC simulates the following hardware:
• CPU: Sort of G3, no altivec yet. Includes a minimalistic debugger. The CPU is completely deterministic, optimal for OS-development.
• CPU JITC-X86: A very fast CPU for x86 systems that translates the PowerPC code on-the-fly to native code. Still a little bit experimental.
• PCI-Brige: A barebone PCI-Bridge, enough to work with.
• IDE-Controller: Sort of CMD646 with bus-mastering support. You can attach IDE-Harddisk(s) and/or IDE-CDROM (represented through files or devices on the host).
• PIC: A programmable interrupt controller (sort of Heathrow).
• VIA-Cuda: With attached Mouse and Keyboard.
• Network Controller: Emulates a 3COM 3C90x, works currently only on POSIX with /dev/tun support.
• NVRAM: Capable of storing 8KiB non-volatile memory.
• USB: A non-usable USB-hub, but enough to make the OS think that there is an USB-hub.
• PROM: Sort of openfirmware. Ugly and contains a lot of hacks, but enough to support Yaboot and BootX and to boot from HFS/HFS+ partitions.

Lets hope they survive. I cant really see what Apple would have to complain about. It is supposed to be pretty slow. I guess Expose is out of the question? However for us lowly poor (non powerbook enabled) java developers who would like to test our java programs under os/x, it might provide an option.