Mozilla announced today Project Mortar, an initiative to explore the possibility of deploying alternative technologies in Firefox to replace its internal implementations, as a cost-cutting measure.

The project's first two goals are to test two Chrome plugins within the Firefox codebase. These are PDFium, the Chrome plugin for viewing PDF files, and Pepper Flash, Google's custom implementation of Adobe Flash.

"In order to enable stronger focus on advancing the Web and to reduce the complexity and long term maintenance cost of Firefox, and as part of our strategy to remove generic plugin support, we are launching Project Mortar," said Johnny Stenback, Senior Director Of Engineering at Mozilla Corporation.

"Project Mortar seeks to reduce the time Mozilla spends on technologies that are required to provide a complete web browsing experience, but are not a core piece of the Web platform," Stenback adds. "We will be looking for opportunities to replace such technologies with other existing alternatives, including implementations by other browser vendors."

Firefox lost a massive amount of users, surpassed by Safari

With a market share that has plummeted in the past year, Firefox is losing users and search engine traffic that helps the organization pay the bills.

Firefox development is difficult not only because of the multitude of bugs Mozilla engineers have to fix but also because of the costs that come with having to support a huge staff to fix those issues.

Currently, several sources place Firefox under Safari in terms of market share. Gone are the days of Firefox fighting for the top spot with IE, and here come the days of fighting for the fourth position with Edge.

Browser market share (via W3Counter)

As a direct result of this downward spiral, Mozilla's leadership is looking into cutting down costs by replacing some of their code with open-source projects managed by Google.

"In order to keep costs low, we may use APIs internally that are not considered web standards," Stenback continued. "The project will start by investigating how Firefox handles PDF rendering followed by looking into lower cost approaches to providing Flash support as it’s usage continues to decrease."

Firefox may use the inferior PDFium over PDF.js

For the rest of 2016 and the start of 2017, Mozilla engineers will be testing custom Firefox builds that use the Chromium project's PDFium plugin as Firefox's PDF file handler. Currently, Firefox uses the PDF.js library.

Even if PDF.js is a superior product to PDFium, with many more features, the costs of maintaining PDFium are supported by Google, which is an attractive point for Mozilla.

Asked what would happen to PDF.js, Stenback answered, "This should have no real impact on PDF.js as a standalone project. If our efforts on using PDFium in Firefox gives us a bigger bang for the buck, Firefox will most likely switch to PDFium and no longer use PDF.js though. I don't see why PDF.js wouldn't continue to live on and continue to be used by others."

Nobody will miss the Flash NPAPI plugin

Pepper Flash, which is the custom version of Adobe's Flash Player that ships with some Chromium browsers, is also a bulletpoint on Project Mortar's list, but no tests have been carried out yet.

Firefox still uses the NPAPI (Netscape) version of the Flash Player plugin, but Mozilla said in October 2015 that it plans to ditch all NPAPI plugins by Firefox 53, scheduled for release next year.

Google has designed a newer version of the Flash Player NPAPI plugin, called Flash Player PPAPI plugin (or Pepper Flash), which it began shipping with its browser since version 21, released in July 2012.

"If successful, this work will allow us to completely remove NPAPI support from Firefox once NPAPI is disabled for general plugin use," Stenback said.

According to the official Project Mortar wiki page, if approved, PDFium and Pepper Flash will be added to Firefox as system add-ons. The exact release date has yet to be decided.