@samhenrigold@hachyderm.io you can use `i386_set_ldt` on 64-bit os x to give yourself a 32-bit code segment, maybe you can go the other way and set up a long mode code segment inside of a 32-bit process? or… set up a 32-bit code segment in a 64-bit process, manually map in dyld and the 32-bit frameworks, and jump into dyld_main yourself to host a UI app in a 64-bit process?