Pale Moon is a free and open-source web browser licensed under the MPL-2.0 with an emphasis on customization.

[14] Pale Moon's default search engine is DuckDuckGo and it uses the IP-API service instead of Google for geolocation.

Pale Moon is built upon the Unified XUL Platform (UXP), a cross-platform, multimedia application base that was forked from Mozilla code prior to the introduction of Firefox Quantum.

[10] OS X Lion and above on Apple–Intel architecture and macOS Big Sur and above on Apple silicon processors are supported.

With version 26 in 2016, Pale Moon switched to using the Goanna rendering engine, a fork of Gecko.

[21][31] In 2017, the Pale Moon team began the Unified XUL Platform due to upcoming changes in the Mozilla codebase.

In 2022, a change in direction for Pale Moon was announced to improve website and add-on capability.

[36] A few days later, version 30 had to be recalled due to one of the developers causing issues before exiting the project, such as messing up the add-ons server.