Electrum JS
Electrum is a HD Client for Bitcoin and uses the elliptic curve cryptography to generate addresses. This is a simple client-side script which is capable of generating the addresses from the master public key found in Electrum. This only gives enough access to the web app to read addresses but not spend any balance in them.
The script/application is completely offline except for balance retrieval. It uses Blockr API over SSL for balance determination.
Anybody is welcome to create issues and/or pull requests. I'll be more than happy to merge them. :)