DataMelt

DataMelt (DMelt), maintained by the Knowledge Media Foundation, is free scientific software for numeric computation, statistics, and data visualization — supporting Python (via Jython), Groovy, JRuby, Java, and Matlab/Octave syntax across Windows, Linux, Mac, and Android. It provides access to 50,000+ Java classes for numeric computation and 700+ worked examples, requires no installation (fully portable), and produces publication-quality vector graphics in SVG, EPS, and PDF formats — a real advantage for academic and scientific publishing use cases specifically. It's genuinely free and open source under a commercial-friendly license, with a donation link supporting ongoing development; comprehensive documentation, API references, and a member login system point to an established, actively maintained project. Good fit for a researcher, student, or data analyst who wants a free, cross-platform numeric computing environment supporting multiple scripting languages rather than a single-language tool.