This document discusses JavaScript usage on mobile devices. It notes that smartphones, feature phones, and other mobile devices can support JavaScript via browsers like WebKit. While performance can vary between devices, modern smartphones generally support JavaScript well. The document encourages using tools like PhoneGap to build web apps into native mobile apps, and cautions that touch and click events differ between platforms like iOS and Android. Overall, the conclusion is that JavaScript on mobile is capable with some variations to consider across platforms.