SRWare Iron

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Sidekick Browser

Falkon is a free and open-source Chromium-based web browser built on the Qt WebEngine. It aims to be a lightweight web browser available through all major platforms. Allowing you to enjoy a fast and safe browsing experience from any of your devices. With Falkon you can expect all features found in modern-day browsers like bookmarks, history, sidebars and tabs, while also allowing you to extend the core functionality of the browser with plugins. The project is openly developed by the KDE team and is released as free and open software under the GPL-3.0 License.

A privacy, security and freedom focused web browser forked from Firefox. LibreWolf is always built from the latest Firefox stable source, for up-to-date security and features along with stability. It uses more than 500 privacy, security, performance settings, patches and LibreWolf-Addons, and is designed to minimize data collection and telemetry performed via Firefox's updater and crashreporter.

Otter Browser is a cross-platform, free and open-source web browser that is designed to be very modular. With Otter Browser, the user can replace whole bookmarks manager or history viewer by the use of plugins and the built-in abstraction layer. The browser is built with the Qt WebEngine as a wrapper around Chromium and released under the GPLv3 and is available for Linux, macOS, and Windows platforms.

Sandcat is a free and open-source browser designed for penetration testers and is used for testing security holes and bugs in websites and web applicaitons. The Sandcat Browser is developed by Syshunt on top of Chromium and uses the Lua programming language to provide extensions and scripting support. Although the browser is directed towards system administrators and penetration testers, it can be useful for people who want to verify in real-time how they are tracked online.

Lucid Browser is a free and open source mobile web browser designed to be lightweight, fast, and simple. The application is designed for quick start-ups and simplistic, while still providing features seen in other popular mobile web browser.Lucid Browser is available for Android and weighs in at only 4MB in total.