Free and Open Source Software
Apache Cassandra
Apache Cassandra is a free and open-source, distributed, wide column store, NoSQL database management system. Apache Cassandra is designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. The database has become the choice of many organizations that need scalability and high availability without compromising performance. Apache Cassandra also provides support for replicating across multiple datacenters, providing lower latency for end users of Cassandra-powered applications.
RethinkDB
RethinkDB is a scalable, open-source database designed for real-time applications. When your app polls your database for data, it becomes slow, unscalable, and cumbersome to maintain. RethinkDB solves this by providing a new database access model, where developers can instruct the database to continuously push updated query results to their applications, without polling.
Dokku
Dokku is a free and open-source project that helps you build and manage the lifecycle of applications. With Dokku developers can setup their own PaaS (Platform-as-a-Service) in a matter of minutes. Dokku provides extra plugins which can be used to manage database, and tools needed for your application. If you need to server your application over HTTPS, Dokku got you covered as well, with the help of Let's Encrypts free TLS certificates.
Opera GX
Opera GX is a free gaming-centric web browser developed by Opera Software AS. The browser provides native integration to Discord and other chat applications and day and night mode built right into the browser itself. Opera GX was first announced at E3 2019 and is still in early access.
Apache HBase
With Apache HBase manager realtime read/write access to your Big Data. Apache HBase is an open-source, distributed, versioned, non-relational database modeled after Google's Bigtable: A Distributed Storage System for Structured Data. Just as Bigtable leverages the distributed data storage provided by the Google File System, Apache HBase provides Bigtable-like capabilities on top of Hadoop and HDFS.
RedwoodJS
RedwoodJS is a free and open-source fullstack JavaScript framework for the JAM stack. The framework is highly opinionated and utilize the best practises for building fullstack web applications with React, GraphQL, Prisma and relational databases. Redwood is designed to be deployable completely to the Edge via CDNs and serverless functions distributed everywhere. The structure and tools provided by RedwoodJS let's you get up and running quickly, so that you can see your application go from idea to reality.
wikidPad
wikidPad is a Wiki-like note taking application for storing your thoughts, ideas, todo lists, contacts, or anything else you can think of to write down. What makes wikidPad different from other notepad applications is the ease with which you can cross-link your information. Links in a wiki are created by typing in WikiWords. wikidPad allows you to get a better undestanding of your research and documentation and allow you to better explore and rediscover your knowledge.
Perkeep
Perkeep is a set of free and open-source formats, protocols, and software for modeling, storing, searching, sharing and synchronizing data in the post-PC era. Data may be files or objects, tweets or 5TB videos, and you can access it via a phone, browser or FUSE filesystem. Perkeep is openly and actively developed and anyone is free the contribute to the project.
Komodo Edit
Komodo Edit is a free and open source text editor designed for dynamic programming languages, inclduing PHP, Python, Ruby, JavaScript, Perl, Tcl, XML, HTML5, CSS and more. With Komodo Edit you can enjoy a development process supported by syntax coloring, folding, background syntax checking, and excellent auto-complete and code intellisense. Komodo Edit is developed and released as open source software by ActiveState, in an effort to provide an more accessible version of their commercial software Komodo IDE.
SpeedCrunch
SpeedCrunch is a free and open-source high-precision scientific calculator. The application features a fast, keyboard-driven user interface that displays results as you type. SpeedCrunch comes with over 80 built-in mathematical functions, if that's not enough, you can define your own functions. A library of built-in formulas that allows to you to review and insert commonly used formulas is also included. SpeedCrunch can be downloaded for macOS, Linux and Windows, and is licensed under the GNU General Public License.