High Quality Content by WIKIPEDIA articles! A/ROSE (the Apple Real-time Operating System Environment) was a small embedded operating system which ran on Apple Computer`s Macintosh Coprocessor Platform, an expansion card for the Apple Macintosh. The idea was to offer a single "overdesigned" hardware platform on which 3rd party vendors could build practically any product, reducing the otherwise heavy workload of developing a NuBus-based expansion card. However, the MCP cards were fairly expensive, limiting the appeal of the concept. A/ROSE saw very little use, apparently limited solely to Apple`s own networking cards for serial I/O, Ethernet, TokenRing and Twinax.