[qertoip]

XMR is great but no, it does not have Bitcoin core devs developing for it. And no, nullc did not implement bulletproofs for Monero. Maybe you meant nullc designed confidential transactions. A modified variant of CT was then implemented independently in Monero by Monero devs.

[BTCOG]

I must admit to not following recent XMR development much the last couple years and last recall after Maxwell wrote bulletproofs that it was intended to be implemented. I did check and see that it had been re-written and implemented by another in a different custom-tailored way. I do pay the XMR guys respect for doing their thing and branching their way. No disrespect, I should have generally said that the Bitcoin core devs have paved work for them. No, I did not mean core devs are writing all XMR code.

https://eprint.iacr.org/2017/1066.pdf