As you might know, a BOINC-platform is a combination of hardware (the CPU-architecture) and software (the OS running it) (Click to make bigger)
All in all a x86 and x86-64 whitewash. But with the Apple ARM silicon (Apple M1, M2 & M3) and the upcoming Armv9 Neoverse SOCs, the lower part of this table might get filled too.