What is Open-Transactions?
Open-Transactions is an easy-to-use, financial crypto, digital cash and transaction library.
Open-Transactions includes a client API, a working server, a GUI test wallet (in Java) and a command-line wallet utility.
Open-Transactions features: a large variety of financial instruments, markets, basket currencies, unforgeable account balances, digital cash, destruction of account history, Ricardian contracts, Smart Contracts (scriptable clauses), and more.

What does it do?
Open-Transactions allows users to issue and manipulate digital assets.
Any issuer can sign and distribute new currency contracts in order to create new digital asset types.
Users may create many pseudonyms (public keys), each of which may own asset accounts of various types, on OT servers.
Users can operate "cash-only" (without accounts) for maximum anonymity, using unlinkable digital cash.

Financial Instruments
Users can transfer digital assets securely and provably, with receipts signed by all parties.
Even an OT server cannot change balances, or forge transactions--since it cannot forge your signature on your receipt.
Open-Transactions supports a range of financial instruments such as account transfer, cheques and vouchers (aka "cashier's cheques" or "banker's cheques"), in addition to cash.
These instruments are all analogous to the same financial instruments that we all use at normal banks today. Everyone already has an intuitive understanding of these financial instruments, because we use them regularly in our normal daily lives.

See also: http://cur.lv/74cgx