Cross-compiling replica of CP2 compiler
CP2 is the standard compiler shipped with BlackBox Component Framework. It is not cross-compiling: it compiles modules on the base of modules in the current (running) system, which the compiler is a part of.
Cross is a slightly modified version of CP2 that performs cross-compilation: that is, it can pick up symbol files for imported modules, and output symbol and code files for compiled modules, from and into explicitly specified primary and secondary bases (directories).