Software for Java
QuestDB
QuestDB is a relational column-oriented time series database designed for real-time analytics on time series and event data. It uses the SQL language and include extensions for time series data. QuestDB is released as free and open source software and distributed as a single binary including a trimmed version of the JVM (Java Virtual Machine) weighing in at only 24.5 MB.
Grails
Grails is powerful Groovy-based web application framework for the JVM built on top of Spring Boot.
XWiki
Developed for more than 10 years, XWiki is a long standing project trusted by individuals and high profile corporations. XWiki is a free and open source Wiki software written in Java and released under the GNU Lesser General Public License. XWiki provides a WYSIWYG editing, OpenDocument based document import/export, semantic annotations and tagging, and advanced permissions management fit for enterprise use. The extensible XWiki platform allow you to customaize and improve your Wiki as the content, userbase or usecase grows and evolves.
SQuirreL SQL
SQuirreL SQL is a free and open-source SQL client and database administration tool. SQuirreL SQL is written in Java and uses JDBC to allow users to explore and interact with databases via a JDBC driver. With SQuirreL SQL you can manage your database through a graphical user interface where you can create and drop tables, add columns and rows, create function and query your data. The software is openly developed and released under the GNU Lesser General Public License which makes it free to use.
Temporal Workflow
Temporal Workflow is a free and open-source workflow and automation tool. With Temporal Workflow you can build and operate resilient applications using developer friendly primitives. Focus on writing business logic instead of glue code and Temporal Workflow will take care of the rest.
Flyway
Flyway provides open source, enterpise-grade version control for your database. By allowing your application to have a robust schema evulotion across all your environments, you can restasured that your applications are built safer and faster. With Flyway you can manage your database with plain old SQL and perform migrations for advanced data transformations and handling with LOBs and drop all tables, views, triggers, and more from a schema without dropping the schema itself. Flyway also integraties with cloud database provides and third-party hosting platforms such as Amazon RDS, Microsoft SQL Azure, Google Cloud SQL, Heroku, and more.
VRaptor
VRaptor is a free and open-source MVC framework written in Java. VRaptor is used to develop web applications on top of CDI (Contexts and Dependency Injection for Java EE). The framework features tools that allow developers to maintain a high productivity and a developer experience loved by many. The VRaptor community consist of seasoned developers that freely build and distribute the framework free of charge.
muCommander
muCommander is a lightweight, cross-platform file manager with a dual-pane interface. The application runs on any operating system with Java support including macOS, Windows, Linux, BSD and Solaris. Featuring a virtual filesystem with support for local volumes, FTP, SFTP, SMB, NFS, HTTP, Amazon S3, Hadoop HDFS and Bonjour. With muCommander you can quickly copy, move, rename files, create directories, email files and zip files can be modified live without the requirement of re-compressing entire archives. muCommander is released as free and open source software under the GNU General License.
Vaadin
Vaadin is an open-source framework for web application development. The framework allows you to write UI 100% in Java without having to write extra HTML, CSS and JS. Vaadin apps run on the server and handle all communication automatically and securely.
ZK Framework
ZK is anopen source Java framework for building enterprise web and mobile apps.
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.
Apache NiFi
With Apache NiFi you can automate the flow of data between software systems. Apache NiFi supports powerful and scalable directed graphs of data routing, transformation, and system mediation logic. Apache NiFi is highly configurable and provides an intuetive web-based user inferface that can be used to control and monitor your data flow. The software is developed by the Apache Foundation and released free and open-source under the Apache License 2.0.
Apache Chemistry
Apache Chemistry provides open source implementations of the Content Management Interoperability Services (CMIS) specification. Libraries are available for Java, Python, PHP and .NET.
Socket.io
Socket.IO is a free and open-source JavaScript library that can be used for building realtime web applications. The library consists of two parts, a server-side library for Node.js and a client-side library that runs in the browser.