Android is an operating system based on the Linux kernel, and designed primarily for touchscreen mobile devices such as smartphones and tablet computers.
Cyanogenmod (CM) is custom OS/ROM for Android devices. CM is based on (AOSP) Android Open Source Project code. CM is an alternative operating system intended to replace the...
Ubuntu Touch is a mobile version of the Ubuntu operating system primarily for touchscreen mobile devices such as smartphones and tablet computers.
Sailfish is a Linux-based mobile operating system primarily targeted at mobile phones.
Windows 10 Mobile / Windows Phone
Windows 10 Mobile (previously Windows Phone) is a series of proprietary smartphone and tablet (under 8-inch) operating systems developed by Microsoft.
PrivatOS is an Android KitKat fork that's running on BlackPhone.