[Cryptography] Aggregate signatures

[xor]

I'm a programmer, I need a way to have several people sign the same
message, and then send that message to several other people. I'd like to
be able to scale 'several people' to up to a million, so a list of
individual signatures doesn't work so well. I'm not sure what
cryptographic tool I require, but I'm looking into aggregate signatures.
Something like this:

http://theory.stanford.edu/~dfreeman/cs259c-f11/finalpapers/aggregatesigs.pdf

I couldn't find however a single implementation, I couldn't find one in
openssl, nss, or anywhere else. Does anyone know of a decent
implementation? Does anyone know if there is even a standard?