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Building Systems with Mathematica
Mathematica has everything you need to create complete systems for technical and non-technical applications.
Combinatorica is a system for doing discrete mathematics that comes as a standard add-on package with Mathematica.
WorldPlot is another standard add-on package that comes with Mathematica.
Optica is a large Mathematica package for doing optical engineering.
Mathematica has made possible a new generation of notebook-based educational courseware.
Follow this link to see a simple example.
Technical Trader is a Mathematica system for financial analysis.
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Any system you build in Mathematica will run unchanged across all computer platforms.