As outlined on the Mozilla Blog earlier this year, the PDF viewer arrived from the Mozilla-supported PDF.js project, and was in part triggered by existing plug-ins potentially exposing users to security vulnerabilities.
The integration of a native solution for PDF viewing also aligns with Mozilla’s increasing shift away from plug-ins, most clearly highlighted in its embracing click-to-play technology.
The company added that in using standard HTML5 APIs, the new PDF viewer is capable of running on various platforms, which will no doubt further its plans on mobile, such as through Firefox OS.
On Android, the latest update doesn't yet include the PDF viewer. Instead, it's mostly designed to make Firefox available on more devices. According to Mozilla, by making Firefox work with ARMv6 processors, its potential market has expanded by more than 15 million smartphones, which include the likes of the LG Optimus One, T-Mobile’s myTouch 3G slide, HTC’s Wildfire S and ZTE’s R750. The new Android release also introduces themes, enabling users to personalise the mobile experience with just a few taps.