Free Software for Self-Hosted
Calendso
Calendso is a free and open source self-hosted Calendly alternative. Calendso is white-label by design and can be hosted on-premise or can be hosted and managed by Calendso for a monthly charge. The calendar software is built to be API-driven and ready to be deployed on your own domain and does not add hurdles to the self-hosting process to favor the managed solution. Calendso provides modern features and comes with integrations for popular third-party services like Salesforce, Zapier, HubSpot and many more. While also allow you and your company to build custom integrations for any platform out there, and integrate seamlessly with your existing workflow.
OpenStack
OpenStack is an IaaS (Infrastructure-as-a-Service) and cloud computing platform developed by the OpenStack Foundation. The project was first started in 2010 as a joint venture by Rackspace Hosting and NASA. OpenStack both free and open-source and allows you to create public or private clouds with distributed virtual servers. The OpenStack dashboard can be used by administrators of the cloud to empower user, provision resources and track the overall health of the network and infrastructure.
Django Rest Framework
Django REST Framework is a free and open-source, powerful and flexible toolkit for building Web APIs with the Python framework, Django. With Django REST Framework it easy to create full-fledged REST APIs that follows the Django design pattern with models, views and urls. It comes with authentication policies including packages for OAuth1a and OAuth2 and a pre-built browsable API, much like Swagger.
Svelte
Svelte introduces a radical new approach to building user interfaces with JavaScript. It is a compile-based component framework that builds efficient code that updates the DOM. Where most traditional frontend JavaScript framework does most of their work in the browser, Svelte includes that work in the compilation process when you build your app. This creates a smaller app which ultimately leads to faster load times and a better experience for the end-user.
Caddy
Caddy is a powerful, enterprise-ready, open-source web server written in Go. The Caddy provides automatic SSL/TLS cretificates so that your application always is served over HTTPS.
MainWP
The MainWP WordPress plugin is a free and open-source, self-hosted solution for managing multiple WordPress sites from a single dashboard. With MainWP you can manage posts and pages, controlling users, making backups and performing updates through the unified MainWP dashboard. All of which will minimize the time and cost of maintaining multiple WordPress sites.
Metabase
Metabase is an open-source tool that allow data and analytics to be shared fast and easy within a company. The open-source business intelligence server provided by Metabase can be installed within 5 minutes. Metabase can also, easily be integrated with third-pary services and databases like Amazon Redshift, Druid, Google Analytics, Google BigQuery, H2, MongoDB, MySQL, Oracle, PostgreSQL, Presto, Snowflake, SparkSQL, SQL Server, SQLite and Vertica. The software is provided free and open-source under the GNU Affero General Public License (AGPL) and managed server solutions can be purchased at a monthly subscription.
Grafana
As the world's most popular free and open source technology for visualizing metrics, Graphana makes it easy to create a interactive dashboard for data monitoring. Grafana's designed from the ground-up for analyzing and visualizing metrics such as system CPU, memory, disk and I/O utilization. All metrics provided by connected data sources and applications can be visualized and monitored though charts, graphs, and alerts. You can also extend the core functionality of Graphana through a built-in plug-in system. Popular companies and applications like Uber, Robinhood, Nubank and others trust Graphana and its real-time visualization and monitoring capabilities.
Memcached
Memcached is a free and open-source in-memory key-value store used for storing small chunks of data objects in dynamic memory. Most commonly, Memcached is used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an data sources needs to be fetched. Rather than querying the database for each unique request, Memcached can be used to store data from common pages in memory and speedup and improve the experience of a web application or website.
Babel
Babel is the next generation free and open-source JavaScript compiler and toolchain. The Babel toolchain is mainly used to convert ECMAScript 2015+ code into a backwards compatible version of JavaScript to be compatible with older browser versions. Babel can transform syntax, polyfill features that are missing for your targeted environments, perform source code transformations and more.