Interoperating? Is the iMessage spec public? Can I use iMessage on an android phone without hacky workarounds like using a mac computer? Come to think of it,

Interoperating? Is the iMessage spec public? Can I use iMessage on an android phone without hacky workarounds like using a mac computer? Come to think of it, the same lack of interop openness applies to airdrop, use of the on-phone NFC chipset (for uses other than apple-pay), and a bunch of other such things.