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.
The Two-Layered GUI Toolkit is a library of GUI helper classes which is designed in a way to simplify development of separate interchangeable front-ends. For every supported dialog box type, there is a settings class (independent from a GUI toolkit) whose options can be used by one of the implementations for a specific GUI toolkit (bindings for Gtk#, WPF, and WinForms are provided, but custom ones can be added). That is, the dialog definition can be prepared by the application's core component and passed to the front-end, which uses it to instantiate the dialog box using whatever GUI toolkit it likes.
Tree Layout Helper is a .NET/Mono library that provides some utilities for handling tree structures. Most importantly, it supports the display of tree structures as two-dimensional graphics. By using ready-made interfaces, you can specify the size of your nodes, and the Tree Layout Helper library will take care of placing those nodes appropriately.
Caffeine is a free high-performance interoperability solution between the Java platform and the .NET framework, with special emphasis on the enterprise variants of such platforms. It makes software originally written for .NET available to the Java platform. It promotes library reuse between Java and .NET by transferring APIs across environments, and allows code written for one platform to run on the other platform with minimal performance degradation. It is powered by Mono, and runs on Alpha, Linux, Windows, Mac OS X, HPPA, SPARC, and s390 systems.
Appomattox is a project to build a set of cross-platform mapping objects for the .NET framework. It is also a desktop GIS application. It currently supports the following data sources: shapefiles, raster data (JPEG, GIF, TIFF, bitmap, and PNG), and PostGIS. The goal of Appomattox is to provide an elegant and intuitive user interface for mapping and Geographic Information Systems (GIS) without sacrificing power and functionality.
Flexible Localization is a .NET/Mono library for string-based user interface localization. It offers a hierarchical structure (which can be partially loaded) to organize the strings, as well as support for several independently-localized modules. Localization files are validated against a localization declaration which defines the actual strings that are expected to be in the localization files. The strings themselves can be parametrized and evaluated based on expressions (i.e., different strings can be returned by a localization, based on parameter values).
A two-factor authentication system.
A seed project that combines Play Framework, AngularJS, Bootstrap, and MongoDB.