Sourcetrail is a productivity tool for software developers on Windows, Mac and Linux. It uses static source code analysis to provide a visualization that lets you follow calls and other dependencies.
A free (libre), open-source (GNU LGPL) web-conferencing system developed with support from the Mozilla Foundation's WebFWD project. Designed for online education, BigBluebutton provides voice- and video-conferencing capabilities that include conference recording, presentation uploads, virtual whiteboard, and simultaneous webcam users.
The BigBlueButton server runs on Linux, but virtual machine images are available for running the server on other platforms.
Eclipse is an open-source community project that is focused on building an extensible development platform: a suite of software tools that assist in the writing of software. Primarily it is used as a Java integrated development environment (IDE) but has been adapted for many other languages including python, C, C++, and FORTRAN.
The Visualization Toolkit (VTK) is an open-source, freely available software system for 3D computer graphics, image processing and visualization. VTK consists of a C++ class library and several interpreted interface layers including Tcl/Tk, Java, and Python.