Bitcoin Armory is a full-featured, open source Bitcoin client promising a dozen features not found in any other client software.

Manage multiple wallets (deterministic and watching-only), print paper backups that work forever, import or sweep private keys, and keep your savings in a computer that never touches the internet, while still being able to manage incoming payments, and create outgoing payments with the help of a USB key.

Multi-signature transactions are accommodated under-the-hood and will be completed and integrated into the UI soon.

Armory has no independent networking components built in. Instead, it relies on the Satoshi client to securely connect to peers, validate blockchain data, and broadcast transactions.