What are some alternatives?
When comparing CopperheadOS and LineageOS, you can also consider the following products
Replicant - Replicant is a distribution of Android that is 100% Free Software.
MIUI - Xiaomi MIUI Official Global Site. MIUI is a customized Android ROM developed by Xiaomi for smartphones and tablets. MIUI Forum offers ROM downloads for 251 devices including Mi 6, Mi MIX 2, Redmi Note 4 and others.
Android - Android is an open source mobile operating system initially released by Google in 2008 and has since become of the most widely used operating systems on any platform.
Ubuntu Touch - Read more about Ubuntu Touch. Our free and open source mobile OS is made and maintained by UBports! We care about your freedom and privacy.
Resurrection Remix OS - Resurrection Remix ROM is ultimately full featured, stable and combined with the best features of...
AOKP - AOKP stands for Android Open Kang Project. It is a custom ROM distribution for many Android devices.