German developers are working on an OpenPGP implementation in javascript is written. The first result is now released: an extension for the Chrome browser that Gmail users the encryption.
Developers of the German Recurity Labs have an early version of GPG4Browsers released. The project is an attempt encryption standard OpenPGP to browsers. Going to a Chrome extension that, in combination with Gmail works.
Encrypt and decrypt mail is already working, as well as signing and verifying of signatures, and the im – and export of certificates. The generation, manipulation, and creation of signatures on keys, making encrypted messages with only symmetric encryption and the use of compressed datapackets does not work yet, and also some handtekeningentypes keys not yet supported.
OpenPGP, a continuation of PGP, is already in most mail programs are supported, but support for webmail is still limited. There was, however, a number of years ago, a Firefox add-on, Freenigma, with support for Gmail, Hotmail and Yahoo Mail. The source code of GPG4Browser is released under the lgpl 2.1 license.