Pale Moon for Android was a distinct development effort that is no longer maintained.
Pale Moon 27.9.4 was the last release to officially support Windows Vista as well as the final community-contributed release for Mac OS X 10.6 Snow Leopard. Two speciality builds continued to support XP for some time: PM4XP, which was discontinued after release 25.7.0, and a special build intended for devices with Intel Atom processors, which was discontinued with the release of Pale Moon 27.0.0. Official support for Windows XP ended with Pale Moon 25.0.0. Since March 2021, macOS is no longer supported however, this decision has since been reconsidered, and Pale Moon may return to macOS in a future release.
These repositories provide the latest Pale Moon updates only for recent Debian and Ubuntu major releases.
Moonchild Productions also provides a portable version of Pale Moon for Windows. On Linux, specific versions of GTK 2 or 3, GLib, Pango, and libstdc++ are required. For Windows, the only requirement is Windows 7 with Service Pack 1 or newer. An SSE2-capable processor is required to run the official Pale Moon releases, regardless of operating system choice. Moonchild Productions offers Pale Moon for modern iterations of the Microsoft Windows and Linux operating systems. The name and logo are trademarked by the project founder and cannot be used without his prior permission. To ensure quality, redistribution of officially branded Pale Moon binaries is only permissible under specific circumstances.
Pale Moon's source code is released under the Mozilla Public License 2.0 except for parts relating to branding. UXP is a fork of the Firefox 52 ESR platform, created in 2017 to address the imminent death of XUL/XPCOM technology in the Firefox codebase.
Moonchild Productions develops UXP alongside Pale Moon. It includes the Goanna layout and rendering engine, a fork of Mozilla's Gecko engine. Pale Moon is built upon the Unified XUL Platform (UXP), a cross-platform, multimedia application base with ancestry in Mozilla code.