Christian Bauer (developer of a Mac 68k emulator ShapeShifter for Amiga) released the first version of Basilisk II in March 1999. The emulator was expected to be highly portable across several computing platforms[3]: 36 and provided some improvements in comparison to ShapeShifter - e.g. no limit for number of emulated disks, improved CD-ROM support and support for the host file system.[4] However, early reviews highlighted several issues like difficult configuration and limited compatibility with recommendation of ShapeShifter as a better choice for Amiga users.[3]: 37 [4] Newer releases mitigated these problems, 2005 review of the MorphOS version noted only slow CPU emulation (in comparison to built-in 68k CPU emulation for Amiga applications in MorphOS) as a major issue.[5]: 25
The latest version of Classic Mac OS that can be run within Basilisk II is Mac OS 8.1,[6] the last 680x0-compatible version, released in January 1998. Mac OS 8.5, which came out nine months later, was PowerPC-only and marked the end of Apple's 680x0 support.