PyQtGraph is a pure-python graphics and GUI library built on PyQt4 and numpy. It is intended for use in mathematics / scientific / engineering applications. Despite being written entirely in Python, the library is very fast due to its heavy leverage of numpy for number crunching and Qt's GraphicsView framework for fast display.

rbenv lets you easily switch between multiple versions of Ruby. It's simple, unobtrusive, and follows the UNIX tradition of single-purpose tools that do one thing well.

Node is an event-based server-side JavaScript engine.

pdf2svg is a tiny command-line utility using Cairo and Poppler to convert PDF documents into SVG files. Multi-page PDF can be split up to one SVG per page by passing a file naming specification.

This package provides signal processing tools including filtering, windowing and display functions in octave.