Free Software for Self-Hosted
Graylog
Graylog is a open-source, leading centralized log management solution built to open standards for capturing, storing, and enabling real-time analysis of terabytes of machine data. We deliver a better user experience by making analysis ridiculously fast, efficient, cost-effective, and flexible.
TiddlyWiki
TiddlyWiki is a personal wiki and a non-linear notebook that provides an interactive way to manipulate and structure data for web consumption. The free and open source application is written as an SPA (Single Page Application) with JavaScript by Jermolene. TiddlyWiki is designed from the ground up to easy to customize and re-shape depending on your use-case, while also providing tools that can be used to split up and reuse content.
Vue.js
Vue.js is a free and open-source intuitive and composable MVVM framework for building interactive UIs with JavaScript. The library was first created and released by Evan You back in 2014, and saw a meteoric rise in the open-souce community. Possibly due to the accessible nature of the project and the library itself. With Vue.js you can get started by simply importing the script via CDN, and start building. Today, Vue.js is used in a multitude of web applications and powers interactive interfaces for people to enjoy across the globe.
PostgREST
PostgREST is a standalone web server and development tool that automatically turns your PostgreSQL database into a RESTful API.
Ionic Framework
Ionic is an open-source mobile app development framework that makes it easy to build high quality native and progressive web applications. The Ionic Framework takes advantage of power and flexibility of Angular to enable developers to build production-ready applications in a way that feels familiar. The Ionic Framework is released free and open-source under the MIT License, but the company behind the framework also provides the Ionic Enterprice Platform which enables large organization to launch enterprice-grade applications faster to the cloud.
LevelDB
LevelDB is a free and open-source key-value storage library developed by Google. LevelDB provides on-disk storage and ordered mapping of string keys to string values. With LevelDB data is stored and sorted by key, and the keys and values are arbitrary byte arrays. The library will also automatically compress files using the Snappy compression library to optimize for storage capacity.
Sinatra
Sinatra is a free and open source DSL library for quickly creating web applications in Ruby with minimal effort. Sinatra is loved by many due to its simplicity and ease-of-user. For Ruby developers, Sinatra is an alternative to web application frameworks like Ruby on Rails, Merb, Nitro, and Camping.
Elasticsearch
Elasticsearch is an open-source, highly scalable search and analytics engine written in Java. The engine is built ontop of Apache Lucene Library and has an advanced distributed model and consistent API interface. Elasticsearch allows you to store, search, and analyze huge volumes of data quickly and in near real-time with answers provided in milliseconds. Making it perfect for building full text search, analytics store, auto completer, spell checker, and alerting engines.
MemSQL
MemSQL is a free and open-source all-in-one relation database management system. The database lends itself for operational analytics and AI/ML-powered applications that requires fast data ingest, high performance queries and elastic scaling. MemSQL supports ANSI SQL and blended workloads, commonly referred to as translytical, HTAP, HOAP, and ATP workloads. The developer MemSQL Inc, also provides commercially hosted version of the database called MemSQL Helios, a cloud database-as-a-service.