Linux Softwares to Extensible by Plugins/Extensions

Komodo IDE is a powerful and flexible integrated development environment designed for building dynamic web applications.

Qt Creator is a powerful, cross-platform Integrated Development Environment (IDE) tailored for building applications with the Qt framework. It supports C++, QML, and JavaScript, offering a comprehensive suite of tools for designing UIs, writing code, debugging, and deploying software across various platforms.

Light Table is an innovative code editor designed to provide developers with instant feedback and a deeper connection to their code. It offers a clean and customizable interface, focusing on interactive development and visualizing data flow.

Mutt is a highly configurable, text-based email client for Unix-like systems. It offers powerful features for advanced users who prefer a lightweight and efficient email management experience directly from the command line.

Nightingale is a highly customizable cross-platform audio player with a focus on extensibility, featuring a beautiful interface, a wide array of supported formats, and tools like media library management, podcast playback, and integrated web browsing.

CodeLite is a free, open-source, and cross-platform Integrated Development Environment (IDE) designed specifically for C, C++, PHP, and JavaScript (Node.js) development. It provides a feature-rich environment to streamline the coding process for these languages.

Gajim is a free and open-source instant messaging client for the XMPP protocol. Built using the GTK+ toolkit, it offers a wide array of features for secure and flexible communication, including encrypted chat, group conversations, multi-protocol support via gateways, and extensive customization options.

Nylas Mail, an extensible open-source email client, offers a unified inbox, robust search, and calendar integration. It supports multiple accounts and provides features like email tracking and undo send, aiming to enhance productivity and email management for users.

Haroopad is a discontinued markdown-enabled document processor designed for creating web-friendly content. It offers a distraction-free writing environment with live preview and syntax highlighting, making it suitable for bloggers, writers, and developers.

Nemo is the default and highly customizable file manager for the Cinnamon desktop environment. It offers a robust set of features for managing files and folders efficiently, including multi-pane views, tabbed browsing, extensibility via plugins, and an integrated terminal for advanced users.

OpenELEC is a small, fast booting embedded operating system built specifically to turn your computer into a Kodi (XBMC) media center. It focuses on simplicity and minimal configuration for a plug-and-play home theatre experience.

Pinegrow Web Editor is a powerful desktop application for visually building websites and WordPress themes with live HTML and CSS editing. It combines the speed of a visual editor with the flexibility of a code editor, supporting popular frameworks like Bootstrap and Foundation.

Redaxscript is an exceptionally lightweight and high-performance Content Management System designed for simplicity and speed.

VMware vSphere Hypervisor, also known as ESXi, is a free, bare-metal hypervisor that allows users to virtualize their server hardware, consolidating applications and improving resource utilization. It provides a robust foundation for building virtualized IT environments.

Gwenview is a robust and user-friendly image viewer for desktop environments, primarily known for its integration with the KDE ecosystem. It offers a clean interface and essential tools for browsing, viewing, and performing basic edits on a wide range of image formats.

PlantUML is an open-source tool that allows users to generate a wide variety of UML and other diagram types from a simple human-readable text description. It supports sequences, use case, class, activity, component, state, object, deployment, timing diagrams, and more, making it accessible and efficient for technical documentation and visualization.

Org-mode is a powerful and flexible mode for GNU Emacs, designed for note-taking, project planning, to-do list management, and authoring documents. It utilizes simple plain text files with intuitive markup.

Nomacs is a fast and lightweight free, open-source image viewer offering a wide array of features for diverse image formats, including RAW and PSD. It provides essential editing tools, batch processing capabilities, and extensibility via plugins, making it more than just a simple viewer.

Fedena is an open-source school management software built on Ruby on Rails, designed to streamline administrative, academic, and communication processes for educational institutions.

Rocket.Chat is a comprehensive free and open-source team communication platform, offering real-time chat, audio/video conferencing, screen sharing, and file sharing. Designed for flexibility, it can be self-hosted on-premises for maximum control and customization, making it ideal for organizations prioritizing data privacy and security.

Firefox Developer Edition is a specialized version of the Firefox browser tailored for web developers. It offers the latest features and tools earlier than the standard release, providing a stable yet cutting-edge environment for building and testing websites.

KDevelop is a powerful, free, and open-source Integrated Development Environment (IDE) designed for Unix-like systems, Windows, and macOS. It offers a robust set of features for a wide range of programming languages, including C++, Python, PHP, and more, making it a versatile tool for software developers.

GNU IceCat is a free software version of the Firefox web browser, distributed by the GNU Project. It focuses on user freedom and privacy by removing proprietary components and incorporating privacy-enhancing features.

Google Desktop was a powerful desktop search application designed to index and rapidly locate information across your computer. It integrated seamlessly with your operating system, offering indexed search for files, emails, web history, and more, along with a customizable sidebar for widgets and gadgets.

Claws Mail is a powerful yet lightweight, open-source email and news client built on GTK+. It's known for its speed, stability, rich feature set, and high degree of customization, making it an excellent choice for users demanding control and efficiency.

Mantis Bug Tracker is a free and open-source, web-based issue tracking system designed primarily for software defect tracking. It offers a straightforward interface and a range of features suitable for managing projects and tracking the lifecycle of bugs and issues.

rTorrent is a powerful and resource-efficient command-line BitTorrent client for Unix-like systems. Built on the advanced libTorrent library, it offers high performance and extensive configurability, making it ideal for users seeking control and automation.

Kopete is a versatile, free and open-source instant messaging client designed initially for the KDE Plasma desktop. It distinguishes itself by supporting a multitude of protocols, allowing users to connect to various chat networks from a single application.

Irssi is a highly customizable command-line IRC client popular among power users and system administrators for its extensibility and efficiency.

AngularJS is a powerful open-source JavaScript framework developed by Google that enables developers to build dynamic single-page applications (SPAs). It simplifies front-end development by extending HTML with its directives and facilitating two-way data binding, promoting a Model-View-Controller (MVC) or Model-View-ViewModel (MVVM) architectural pattern.