phpMoneyBooks is a PHP/MySQL program that aims to be a Web-based QuickBooks replacement. It can manage bank accounts and check registries; manage customers and create statement charges; print statements to bill customers; and display profit and loss reports. The design is modular so that features can be added by any PHP/MySQL developer. With new modules, you can direct the user to a URL. Clients can log in and check their own bills and pay online, create memorized billing cycles with Auto Billing (good for recurring billing), and more.
Moneychanger is a simple client GUI built on top of Open Transactions, a financial crypto library. Moneychanger can be used to create pseudonyms, issue currencies, open accounts, withdraw and deposit cash (untraceable digital cash), write and deposit cheques, trade on markets, and much, much more.
Open Transactions is a solid, easy-to-use, financial crypto and digital cash library, including an API, server, and test client. It features anonymous numbered accounts, untraceable digital cash, triple-signed receipts, basket currencies, and signed XML contracts. It also supports cheques, invoices, payment plans, markets with trades, and other instruments. It uses OpenSSL and Lucre blinded tokens.
Bitcoin is a peer-to-peer electronic cash system that is completely decentralized, without the need for a central server or trusted parties. Users hold the crypto keys to their own money and transact directly with each other, with the help of a P2P network to check for double-spending.
Stock Volatility Calculator is a spreadsheet that downloads free historical stock data from the Yahoo! database and calculates the historical or realized volatility of the selected stock. The standard deviation of prices is plotted alongside the stock price chart. The user can freely change the stock used by entering the ticker symbol into the appropriate field and performing a fresh download. Users are also able to change the date range used for the stock data, the number of days back to use for the volatility calculation, and the number of volatility days to use.