Apps with 'Modular System' feature

Extensible, cross-platform text editor with a rich ecosystem of plugins and themes.

Python is an interpreted, interactive, object-oriented, extensible programming language.

Godot is a fully featured, open source, MIT licensed game engine. It focuses on having great tools, and a visual oriented workflow that can export to PC, Mobile and Web platforms.

Xfce (pronounced as four individual letters) is a free software desktop environment for Unix and other Unix-like platforms, such as Linux, Solaris and BSD.

RetroArch is a graphical frontend for emulators, game engines, and media players.

Drupal is a free software package that allows an individual, a community of users, or an enterprise to easily publish, manage and organize a wide variety of content on a website.

The SeaMonkey project is a community effort to develop the SeaMonkey all-in-one internet application suite. A lighter alternative to Mozilla Firefox.

A system-wide equalizer for Windows 7 / 8 / 8.1 / 10 with channel remapping/copying capabilities.

A JavaScript library for building user interfaces.

"empowering the smart home" - vendor and technology agnostic open source home automation.

Open-source and privacy-first home automation with an emphasis on local control and backed by a worldwide community. Runs on Raspberry Pi or local server.
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ClickUp is an all-in-one project management platform that eliminates the need of using more than one tool for your organization’s workflow.

Bitwig Studio is a multi-platform music-creation system for production, performance and DJing, with a focus on flexible editing tools and a super-fast workflow.

mailcow is a mail server suite based on Dovecot, Postfix, SOGo, Rspamd and other open source software, that provides a modern Web UI for administration.

Tracktion is a multi-platform software for music production, with a modern graphic user interface.