HeuristicLab uses several external libraries with separate licences. We generally only include external libraries when the licence is compatible with the GPL. The following external libraries are currently used by HeuristicLab:

• ​ALGLIB: for mathematics and data analysis (linear regression, random forest, neural networks, LBFGS...) (GPL)
• ​AutoDiff: For automatic differentiation (for gradient descent algorithms e.g. when used to optimize parameters of a symbolic regression model) (LGPL)
• ​DayView: For scheduling active times of hive clients. (GPL)
• ​Scilab interface for .NET: To run Scilab scrips, for instance when optimizing simulation models. (CeCILL license (GPL compatible))
• ​EPPlus: For export of data analysis results to Excel. (LGPL)
• ​LibSVM: Our own .NET port of the Java version of LibSVM (the modified BSD license, GPL compatible)
• ​MathJax: For showing symbolic regression models in mathematical notation (in a browser control). (Apache License, Version 2.0)
• ​MATLAB interface for .NET: For interoperation with MATLAB for instance to run MATLAB scripts when optimizing Simulink simulation models.
• Netron Diagramming Library: For drawing the operator graph. (GPL)
• ​Protocol Buffers (C#): For serialization of data between HeuristicLab and external applications. For instance when optimizing parameters of AnyLogic simulation models. (Custom, GPL compatible, original protobufs licence is "New BSD license")
• Parts of ​SharpDevelop: For all interfaces that support scripting in C# (programmable operator, scripting environment, ...). (LGPL)
• ​SharpZipLib: For handling ZIP archives. (Modified GPL, commercial closed-source apps allowed)
• ​Weifen Luo DockPanel Suite: For the docking UI used in the optimizer. (MIT)

The external libraries are grouped in a separate folder in the source code trunk/sources/HeuristicLab.ExtLibs.