Comment 6 for bug 1233810

I agree curve naming is a mess:

P-256 == secp256r1 == prime256v1

Ah yeah, great;)

Regarding how curve negotiation works:
http://crypto.stackexchange.com/questions/11311/with-tls-and-ecdhe-how-does-curve-selection-work

Regarding non-named, explicit curves: this is unsupported by OpenSSL (only named-curves builtin are supported).

Also:
http://crypto.stackexchange.com/questions/11310/with-openssl-and-ecdhe-how-to-show-the-actual-curve-being-used

curve25519:
Yeah, I'm looking forward to Curve25519+Salsa20/ChaCha20+Poly1305 also. And it is indeed coming to Chrome and Firefox: https://twistedmatrix.com/trac/ticket/6663#comment:39