Free extensible software for linux

DEX Extensible Operating System is an operating system specifically designed for educational and research use. DEX Extensible Operating System allows for the dynamic reconfiguration and customization of various system services using concepts found in extensible operating systems.
It aims to create an operating system design thats easy to understand while having features that are common in todays modern operating systems. Unlike other small operating systems, it is powerful enough to support simple applications that require multithreading and file management.
Its architectural design, with the help of Aspect-Oriented programming, enables easy modification and extensibility. It was developed in C and runs on PCs with 80386 processors or higher.
Enhancements:
- This version is released with a floppy image and the kernel source code.
- The release contains peformance enhancements, source code clean-ups, and a makefile for use with GNU make.

Vexi is a Visual, Extensible, XML Interfaces.

Vexi is written in Java, but compiled into native binaries using GCJ and are combined with launchers that work natively in popular web browsers.

UTUTO XS is a desktop and extensible solution based totally in Free/Libre software. It only includes (and will ever do) free/libre and open source software. But it let users the possibility to install other programs.

UTUTO XS is free/libre software, so their users have a high quality desktop system, with legal rights to use, copy, distribute and modify it according to their needs. UTUTO Xs includes the main common-use software for home, developers, companies, organizations, government users.

J-EAI is the first Open Source EAI built as a free software standards-based solution.
J-EAI is built on:
- XML: XML is the new standard for data exchange between heterogeneous systems. It is normalized by the W3C.
- XMPP: XMPP stands for eXtensible Messaging and Presence Protocol. It is standardized by the IETF and is extremely extensible.
Main features:
Cross organisation integration
- J-EAI has been designed to enable applications integration in process that are not limited to the boundary of a single organisation. Its routing mechanism allows several instances of J-EAI managed by different organisation to be interconnected while keeping all the systems independant.
A J-EAI cluster can serve a single domain
- J-EAI works as a cluster to ensure scalability and high-availability. This is an important feature as organisation deploying EAI data bus become highly dependant of the system: high-availability and scalability is thus a must.
Flexible design and extensible data bus
- The J-EAI bus is entirely based on XML and is design as an extensible architecture. This makes it easy to extend and to integrate with legacy application, whatever the technology they are build-in.
Enhancements:
- This version supports collection nodes in the pub sub module.
- Node collection support increases the flexibility of the publish and subscribe model.
- Several bugs have been also fixed.

Eclipse project is an open source community whose projects are focused on providing an extensible development platform and application frameworks for building software.

Eclipse provides extensible tools and frameworks that span the software development lifecycle, including support for modeling, language development environments for Java, C/C++ and others, testing and performance, business intelligence, rich client applications and embedded development.

A large, vibrant ecosystem of major technology vendors, innovative start-ups, universities and research institutions and individuals extend, complement and support the Eclipse Platform

RemindMe is a tool to help you keep track of important dates and manage your calendar.

RemindMe is extensible using Tiny Scheme.

This is the initial release.

MazeRunner project is a very extensible puzzle game that is also meant to be (somewhat) a Mario clone, featuring good music, graphics (2D), and other features.

SpecTcl (pronounced Spectacle) is a powerful nuclear event data analysis too. NSCL SpecTcl project provides an object oriented C++ framework for histogramming and other data analysis operations.

The Tcl/TK scripting language is embedded as the programs command language, providing the user with a powerful, extensible, command set as well as the ability to build custom graphical user interfaces or extend existing ones.

The Xamine display program provides SpecTcl with a powerful visualization component.