Open Source Photo Editing Software
Krita
Krita is a professional free and open-source painting software created and maintained by artists. The main focus of the project is to create top quality painting tools that everyone can afford and enjoy. Krita features an OpenGL-accelerated canvas, colour management support, an advanced brush engine, non-destructive layers and masks, group-based layer management, vector artwork support and switchable customisation profiles.
GIMP
GIMP is a free and open-source raster graphics editor developed by the Free Software Foundation (GNU). The software is a perfect fit for anyone looking for a free and open alternative to Adobe Photoshop. GIMP can be used for photo retouching, image editing and composition. The software is commonly know within the Linux community but is available under the GPLv3+ licenses for macOS and Windows as well.
Pencil2D
Pencil2D is a simple, yet powerful 2D animation, drawing and painting application that lets you create traditional hand-drawn animation using both bitmap and vector graphics. Pencil2D is released as free and open-source software under the GNU General Public License and uses the Qt framework. With Pencil2D you can seamlessly switch between raster and vector workflows, allowing you to sketch, ink & paint on the go.
Shotwell
Shotwell is a free and open-source image manager designed to orginize personal photos on Linux and the GNOME desktop environment.
Akira UX
Akira UX is a free an open-source graphic design software built with Vala and GTK. The application offers a fast approach to UI and UX Design, mainly targeting web designers and graphic designers. Akira UX is available for all major Linux distributions, and through the elementary OS AppCenter.
PhotoPrism
PhotoPrism is a free and open-source server-based application for browsing, organizing and sharing your personal photo collection. PhotoPrism makes use of the latest technologies to automatically tag and find pictures without getting in your way. With PhotoPrism, you can say goodbye to solutions that force you to upload your visual memories to the cloud with big tech cloud providers.
Openverse
Openverse is a platform for Creative Commons licensed digital works created by Automatic, the company behind WordPress. With Openverse you can browse through and download over 600 million artworks for reuse. Openverse is available as a web application and can also be accessed with a dedicated WordPress plugin.
Whitestorm.js
WhitestormJS is a free and open source framework that can be used to build 3D web applications using Three.js technology. WhitestormJS uses Three.js for rendering your scene and objects and Physi.js for simulating physics. Both those libraries are already included in the build and should work properly out-of-the-box. Developers use WhitestormJS to build interactive 3D applications for the web.
Universal Media Server
Universal Media Server is a free and open-source media server capable of serving videos, audio and images to any DLNA-capable device. The software is regularly updated and has more features than any other media server, including paid media servers. Universal Media Server supports streaming to consoles like PS3, Xbox One, Xbox 360 and TVs like LG, Panasonic, Philips, Sharp, Samsung, Sony, and Vizio.