Free 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.
AppCenter
AppCenter is the software store that comes bundled with every release of elementary OS. The store allows users of elementary OS to download curated software specifically built for the operating system. The AppCenter operates under a Pay-What-You-Want pricing model which allow developers to earn money from their open-source creations. Anyone is free to create apps for elementary OS as long as they follow the design guide lines provided by the elementary project.
Docker
Docker is an open-source platform that automates deployment and development life cycles with OS-level virtualization. These virtualization are called containers and contain application specific operating system, software and configurations that are built on deployment. Containers are encapsulated and work across systems, be it in local development or on production servers, they run anywhere. Docker provides a Community Edition (CE) and an Enterprise Edition (EE) and can be used for personal and enterprise level projects alike.
Android
Android is a free and open source mobile operating system built on-top of the Linux kernel. The OS is used by over 150 million people world-wide, which makes it the most popular mobile operating system on earth. Android is optimized for how you use your phone, helping you manage conversations, organize your day, and connect with the people that matters most to you.
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.
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.
Visual Studio Code
A free and open source IDE based on Electron and Atom, developed by Microsoft. Visual Studio Code or VS Code is an extensible IDE or coding editor that is loved by many developers around the globe. The editor combines a streamlined UI with advanced code assistance, code nagivation and intellisense.
Ricochet
Ricochet is a communications application that uses the Tor network to reach your contacts without relying on messaging servers. It creates a hidden service, which is used to rendezvous with your contacts without revealing your location or IP address. Instead of a username, you get a unique address that looks like ricochet:rs7ce36jsj24ogfw.
Xfce
Xfce is a free and open-source desktop environment for Unix-like platforms, such as Linux, Solaris and BSD.
neo4j
Neo4j is a commercially provided graph database management system developed by Neo4j, Inc. The graph database is fundamentally different to the relational model found in relational database management systems (RDBMS). With Neo4j, each data record, or node, stores direct pointers to all the nodes it's connected to. The database is also designed to perform complex queries with complex connections orders of magnitude faster. Neo4j is ACID-compliant and suited for projects that requires complicated relationship structures.