Open Source Software for Linux
Waterfox
A free and open-source web browser developed specifically for x64, ARM64, and PPC64LE systems. Waterfox is fully customizable and allows users to modify and extend the browser any way the please with WebExtensions and classic-style bootstrap add-ons. The browser also respects your privacy, with no built-in telemetry or data collections (beside version number, for automatic updates). Waterfox is available for all major computer operating systems like macOS, Linux and Windows, and a mobile version for Android.
Apache CloudStack
Apache CloudStack is open source software designed to deploy and manage large networks of virtual machines, as a highly available, highly scalable Infrastructure as a Service (IaaS) cloud computing platform. CloudStack is used by a number of service providers to offer public cloud services, and by many companies to provide an on-premises (private) cloud offering, or as part of a hybrid cloud solution.
Unreal Engine
The Unreal Engine is a game engine and suite of tools and technologies developed by Epic Games. The engine was first released in 1998 as a part of the first-person shooter game Unreal, where the game itself was built on the engine. Today the Unreal Engine has grown into an ecosystem that includes a marketplace for game assets that can help indie developer to develop games and make a living selling game assets them selves. The Unreal Engine is free to use and provides a revenue-share model for developers and has been used to tipple A studios and indie developers to create games in almost every genre, including platformers, fighting games,RPGs, MMORPGs, and many more.
Plasma Mobile
Plasma Mobile is a free and open-source, Linux-based user interface for phones. The project aims to a complete software system for mobile devices that is designed from the ground up to give users control over their information and communication. Plasma Mobile takes a pragmatic approach and is inclusive to 3rd party software, allowing the user to choose which applications and services to use.
Sozi
Sozi is a free and open source, browser-based presentation software using SVG and JavaScript to create animated presentations. Unlike in most presentation applications, a Sozi document is not organised as a slideshow, but rather as a poster where the content of your presentation can be freely laid out. Playing such a presentation consists in a series of translations, zooms and rotations that allow to focus on the elements you want to show.
Fragments
Fragments is an easy to use BitTorrent client for the GNOME desktop environment. It is usable for receiving files using the BitTorrent protocol, which enables you to transmit huge files, like videos or installation images for Linux distributions.
Xfce
Xfce is a free and open-source desktop environment for Unix-like platforms, such as Linux, Solaris and BSD.
OpenBoard
OpenBoard is an interactive whiteboard for schools and universities. With OpenBoard you can use a pen tablet, an interactive whiteboard or even a mouse to write and annotate your course. The software is also designed to be easy to use, yet powerful enough to facilitate most usecases, so that you can focus on your presentation rather than the software itself.
Haskell
Haskell is a free and open-source purely-functional programming language. The language has been around since the 1990's and has pioneered a number of advanced programming language features such as type classes, which enable type-safe operator overloading. Haskell is an open-source project of more than twenty years of scientific research and provides built-in concurrency and parallelism, debuggers, profilers and rich libraries that can be used to build robust applications while following functional programming patterns.
DrJava
DrJava is a lightweight programming environment specifically designed for writing Java. Through its design the IDE foster test-driven software development that leads to scalable and maintainable Java applicaitons. DrJava includes an intelligent program editor, an interactions pane for evaluating program text, a source level debugger, a unit testing tool, and a new code coverage tool.