Apps to Extensible by Plugins/Extensions

MediaMonkey is a comprehensive music manager and audio player designed for serious music collectors. It organizes extensive music libraries, plays various audio formats, syncs with devices, converts audio and video, manages tags, and includes tools for ripping and burning CDs and DVDs. It is ideal for users with large and diverse media collections.

Evolution is a comprehensive personal information manager for the GNOME desktop environment, designed to manage emails, contacts, calendars, and tasks. It provides a unified interface for various communication and organizational needs.

iPhoto was a photo management application developed by Apple for macOS and iOS. It allowed users to import, organize, edit, and share digital photos. Initially part of the iLife suite, it aimed to provide a user-friendly experience for casual photographers.

Babylon is a comprehensive language solution providing dictionary lookups, translation services, and helpful writing tools. It offers a rich database of dictionaries and glossaries across numerous languages, supporting both online and offline access for convenient language assistance.

Songbird was a feature-rich, open-source media player and web browser aimed at music enthusiasts. It offered a unique blend of music discovery, management, and playback functionalities, with extensive customization options through add-ons. Key features included music library management, playlist creation, syncing capabilities for various devices, and integrated web browsing for exploring music-related content.

GIMP (GNU Image Manipulation Program) is a powerful, free, and open-source raster graphics editor used for image manipulation, retouching, composition, and authoring. It supports a vast array of file formats and provides sophisticated tools comparable to commercial alternatives, making it a versatile choice for photographers, designers, and artists.

Notepad++ is a widely-used free and open-source text and source code editor for Windows. Built on the Scintilla editing component, it offers a rich set of features for programmers, including syntax highlighting for multiple languages, code folding, macro recording, and a tabbed interface for managing multiple files efficiently. Its lightweight design ensures fast performance even with large files.

Google Chrome is a widely adopted, multi-platform web browser known for its speed, extensive extension library, and seamless integration with Google services. Leveraging the powerful Blink engine, it provides a fast and secure browsing experience for individuals and businesses alike.

Mozilla Firefox is a powerful, open-source web browser developed by the not-for-profit Mozilla Foundation. Known for its strong focus on user privacy and customization, Firefox offers a fast and secure browsing experience across multiple platforms, supported by a vast ecosystem of extensions.

Budgie is a modern and dynamic desktop environment designed for users seeking a balance of elegance and performance. It emphasizes a clean interface and a highly customizable experience, built with modern technologies.

Flux is a powerful and versatile web design environment crafted for professional web developers and designers. It offers a unique blend of a WYSIWYG editor and robust code control, making it suitable for both visual design and direct code manipulation. With support for modern web standards like HTML5, CSS, and JavaScript, alongside features like Bootstrap integration and a built-in file manager, Flux provides a comprehensive toolkit for building responsive and dynamic websites.

Pimcore is an open-source data and experience management platform that integrates Product Information Management (PIM), Digital Asset Management (DAM), Customer Data Platform (CDP), and Web Content Management (WCM). It enables businesses to centralize, manage, and deliver digital data across various channels, facilitating rich customer experiences and streamlined e-commerce operations.

Hex Workshop is a comprehensive hex editor for Windows, offering advanced tools for binary data manipulation, disk editing, and data analysis. It provides a user-friendly interface with powerful features for developers, reverse engineers, and anyone working with low-level data.

LibreELEC is a minimalist, embedded operating system built specifically for running Kodi, the popular open-source media center software. It's designed to be lightweight, fast, and incredibly easy to install and manage, transforming any compatible device into a dedicated media hub.

Sphinx is a powerful and flexible documentation generator written in Python. It takes reStructuredText or Markdown source files and compiles them into various output formats, including HTML, PDF, and ePub. Sphinx is widely used for documenting Python projects but is versatile enough for documenting any type of project or knowledge base.

TeamGrid is a comprehensive project management software specifically designed for marketing agencies. It integrates real-time business analytics, robust time tracking, and flexible task management, providing a centralized platform for planning, executing, and analyzing projects efficiently.

Tkabber is a free and open-source instant messaging client specifically designed for the XMPP protocol. Built with the Tk toolkit, it offers a lightweight yet extensible platform for text-based chat, group conversations, and various interactive functionalities supported by XMPP.

Aurelia is a modern, open-source JavaScript client framework designed for building robust and maintainable web, mobile, and desktop applications, emphasizing simplicity and Convention over Configuration.

Kloxo (Lxadmin) was a free and open-source web hosting control panel designed for managing servers and hosted services on Red Hat and CentOS Linux distributions. Although discontinued, it offered a comprehensive suite of tools for server administration, domain management, email services, and more, primarily targeting shared and dedicated hosting environments.

Awesome HQ is a personalized dashboard and start page solution designed to consolidate your digital life. It offers a highly customizable interface to access your favorite apps, bookmarks, widgets, and information streams from a single, central hub.

Vexor.io is a robust cloud-based continuous integration service empowering development teams to automate their build, test, and deployment processes. It offers flexible configurations and supports various languages and frameworks, streamlining the path from code commit to production.

Eric is a powerful, feature-rich integrated development environment (IDE) primarily designed for Python and Ruby development. Written in Python, it offers extensive capabilities for code editing, debugging, project management, and more, making it suitable for developers of all levels.

Cairo Shell offers a lightweight and modular alternative desktop environment for Windows, aiming to replace the standard taskbar and Start Menu with a more customizable and efficient interface.

Mibbit is a popular web-based IRC client that allows users to connect to various IRC networks and channels directly through their web browser. It eliminates the need for dedicated client software installation and offers a user-friendly interface for real-time text communication.

Xataface is an open-source PHP framework designed to streamline the development of web-based database applications, offering rapid application development capabilities with a focus on MySQL integration.

Form Tools is a powerful, open-source PHP/MySQL form data management script designed for developers and businesses. It seamlessly integrates with existing web forms to capture, organize, and manage submissions through a user-friendly interface, offering extensive customization and extensibility.

PixBuilder is a free and powerful photo editing software for Windows users, offering a comprehensive suite of tools for image manipulation, color correction, and digital drawing. Ideal for both beginners and enthusiasts looking for a capable, no-cost image editor.

CircleCI is a leading continuous integration and continuous delivery (CI/CD) platform that automates the software development process, accelerating build, test, and deployment cycles. It provides developers with the tools to build, test, and deploy applications quickly and reliably across various environments.

Gimp Painter is a discontinued fork of GIMP specifically enhanced with tools for digital painting and drawing. It aimed to provide artists with advanced brush capabilities and performance optimizations tailored for creative workflows on the GIMP platform.

ProcessMaker is a leading open-source digital process automation platform designed to streamline workflow and business process management.