Apps with 'Extensible by Plugins/Extensions' feature
Mozilla Firefox (known simply as Firefox) is a free and open source web browser descended from the Mozilla Application Suite.
GIMP is a free program for such photo retouching, image composition and image authoring. Essentially it's the closest thing to Photoshop you can get for free.
Notepad++ is a free source code editor and Notepad replacement that supports several languages.
LibreOffice is a powerful office suite – its clean interface and feature-rich tools help you unleash your creativity and enhance your productivity.
Code combines the streamlined UI of a modern editor with rich code assistance and navigation, and an integrated debugging experience – without the need for a full IDE.
Extensible, cross-platform text editor with a rich ecosystem of plugins and themes.
Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features.
Blender is the free and open-source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing, video editing, and motion tracking.
A safe home for all your data – Access & share your files, calendars, contacts, mail & more from any device, on your terms.
Full-featured screen recording and live streaming software for Mac, Windows and Linux.
Kodi, formerly XBMC, is a free and open source media player and entertainment center for Linux, Mac OS X, Windows, XBox, and iOS.
Vim ("Vi IMproved") is an advanced text editor that allows syntax highlighting, word completion and has a huge amount of contributed content. It also has a GUI version called GVim.