Finally we have Ajax Secure Service Layer.
From the project home page:
aSSL is a library distributed under MIT License thats implements a technology similar to SSL without HTTPS.
aSSL is composed from a file .js and a server component. Currently, the ASP and PHP components are ready. I'm developing Ruby and Java components and in the near future I will add components in all the principal web languages (Perl, Python, TKL, etc.).
aSSL enables the client to negotiate a secret random 128-bit key with the server using the RC4 algorithm. Once be connection has been established, the data will be sent and received using BlockTEA algorithm (a derivation of DES). aSSL 1.0 uses a 64-bit key. Version 1.1 uses a 128-bit key with a technique similar to Double Key Triple DES, that I call Double Key Quadruple DES. This allows a level of security closer to AES encryption. In fact, aSSL is moving towards AES.