QuantLib is a cross-platform, quantitative finance C++ library for modeling, pricing, trading, and risk management in real-life. It is also wrapped as Python/Ruby/Scheme modules. Extensions for Excel, R, and Mathematica are available. Other such extensions are under consideration. QuantLib offers tools that are useful both for practical implementation and for advanced modeling. It features market conventions, yield curve models, solvers, PDEs, Monte Carlo (low-discrepancy included), exotic options, VAR, and so on.
Admelix is a live CD distribution based on Ubuntu Linux with tools for business administration. Its main objective is to guide managers of small and medium-size businesses towards GNU/Linux and open source software. In addition to the live CD, the project's Web site provides information about open and free tools for business administration.
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.