GTK, which stands for the Gimp ToolKit, is a library for creating graphical user interfaces. It is designed to be small and efficient, but still flexible enough to allow the programmer freedom in the interfaces created. GTK provides some unique features over standard widget libraries.
Drupal is a modular content management system, forum, blogging and community engine. It is database driven and can be used with MySQL, MariaDB, PostgreSQL, and SQLite. Its features include (but are not limited to) discussion forums, Web-based administration, theme support, a submission queue, content rating, content versioning, taxonomy support, user management with a fine-grained permission system based on user roles (groups), error logging, support for content syndication, locale support, and much more. It is considered to be an excellent platform for developers due to its clean code and extensibility, and it can also be used as a Web application framework.
WebGUI is a content management framework built to allow average business users to build and maintain complex Web sites. It is modular, pluggable, and platform independent. It was designed to allow the people who create the content to manage it online, rather than content management taking up the time of busy IT staff. WebGUI comes with a full host of features including shopping cart, subscriptions, forums, photo galleries, FAQs, link lists, blogs, SQL reports, a Web services interface, and a very configurable user privilege and profiling system.
CloverETL is Java-based tool/framework for data integration and creation of data transformations. It is component based and follows the concept of transformation graphs which consist of individual nodes/components performing simple (or complex) operations on data. Any transformation can be defined as a set of interconnected nodes through which data flows. CloverETL can be used as a standalone application or be embedded into a larger project.
GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated. The framework provides a transport abstraction layer and can currently encapsulate the network traffic in UDP, TCP, HTTP, HTTPS, or direct 802.11 (WLAN). GNUnet supports accounting to provide contributing nodes with better service. The services built on top of the framework include anonymous file sharing and a virtual network providing IPv4-IPv6 transition via protocol translation over the P2P network.
Ariadne is a Web Application Framework and Content Management System built with PHP. It allows you to build complex Web applications and sites with ease. It takes care of the mundane stuff like internationalization, security, user management, templating, data retrieval and storage, caching, and site management. It stores content in a structured object store that can be accessed through an extensive filesystem-like API.
Jodd is a Java utility library and set of frameworks. Jodd tools enrich the JDK with many powerful and feature rich utilities. It helps with everyday tasks, and makes code more robust and reliable. Jodd frameworks is set of lightweight application frameworks, compact yet powerful. Designed following the CoC, DRY, and SCS principles, it makes development simple, but not simpler; you get 90% of the features with 10% of the usual effort.
DEMUX Framework enables Java developers to build modular, cross-platform applications which can run on desktop, Web, and mobile and embedded devices. It is based on OSGI and supports creating JavaFX desktop applications, mobiles apps (Android, iOS, Windows), and Web applications.