X25519 for key exchange in TLS is ready and is in openssl master (and in boringSSL). I don't know the status of NSS support, or plans for SChannel and CoreCrypto support.
X25519 key exchange and Ed25519 signatures have been deployed in nacl, libsodium, ssh, etc. for a while.
X25519 for key exchange in TLS is ready and is in openssl master (and in boringSSL). I don't know the status of NSS support, or plans for SChannel and CoreCrypto support.
X25519 key exchange and Ed25519 signatures have been deployed in nacl, libsodium, ssh, etc. for a while.
EDIT: NSS ticket for X25519 Key Exchange: https://bugzilla.mozilla.org/show_bug.cgi?id=957105