Pretty close. Compatibility back to FreeBSD 4 is a port package away, and there's a kernel module to support a.out binaries if you really need to run those 20+

Pretty close. Compatibility back to FreeBSD 4 is a port package away, and there's a kernel module to support a.out binaries if you really need to run those 20+ year old programs. Some of the older syscalls don't have 32 bit wrappers, though, so you may not get full support for absolutely positively everything without emulation, but pretty damn close.