I'd prefer x86-64 related things being kept outside of a Raspberry Pi discussion.
But, since I've been mentioned, I would like to make these clear:
1. I am no coder at all and I am NOT porting anything. I am only trying, from time to time, to COMPILE sources that others have written, using the AROS build environment.
2. PORTING and COMPILING are two very different kind-of efforts. PORTING would mean handling the sources and modifying them to follow rules and best practices I don't even know about. For instance, if I have correctly understood, replacing all 32-bit only structures (LONG?) with 64bit friendly ones. COMPILING just means let those sources build with a 'make' command. The former is a far more difficult operation than the latter.
3. If a program compiles at first, I am happy. If a program does not compile and I can fix this by editing a mmakefile.src file, I'm less happy but more proud of the result. But if a program does not compile due to 64bit incompatibilities, or to other language specific mistakes, or to unknown options (flags?) I should pass the crosscompiler... well... I simply stop and ask more skilled people to do that instead of me.
Do not underestimate the effort needed to PORT a big project from an architecture to another. I wonder how many years it will take, for instance, to port Magellan to x86-64. And, on the contrary of what I've read here, it *IS* a important program to me, since it's the default GUI of my operating environment. Moreover, most of Icaros goodies are available only if Magellan is the working GUI of the system. I'm really not so interested in people "rejecting" it.