65Tube runs a version of 6502 BBC BASIC by emulating 6502 instructions and passing OS calls through a Tube interface to the host RISC OS system.
The host RISC OS here is RISC OS Pyromaniac. RISC OS Pyromaniac is an implementation of RISC OS in Python which emulates ARM instructions and passes the OS calls through a translation later to the host OS.
The host OS here is macOS.
The sources as supplied were:
Modified to remove any dependency on legacy headers
Updated to use the modern build system
Made to build with objasm
Made 32bit safe
Built with the cross compiling tool chain
Glued together using the original glue code (modified for 32bit) under BASIC on Pyromaniac