Download Firefox Version 51 For Mac

Mozilla Firefox for Mac is a fast, full-featured Web browser. The app includes pop-up blocking, tab-browsing, integrated Google, Yahoo and Bing search, simplified privacy controls, a streamlined browser window that shows you more of the page than any other browser and a number of additional features that work with you to help you get the most out of your time online.
Hide your real IP address and protect your privacy while online! Check out HMA! Pro VPN for Mac!
Check out the new Firefox for macOS, which is first of several releases called Firefox Quantum for Mac, getting you to the things you love and the stuff you need faster than ever before, along with a fresh new look.
Features and Highlights
2x Faster
Crazy powerful browser engine? Check. Less time waiting around for pages to load? Also, check. Get the best Firefox yet.
30% lighter than Chrome
Less memory usage means more space for your computer to keep running smoothly. Your other programs will thank you.
Smooth browsing
Whether you've opened 10 or 1000, switching between tabs is faster than ever with the program's new, responsive engine.
Private Browsing
The app blocks online trackers while you browse and won't remember your history after you're done.
Tracking Protection
Some ads have hidden trackers that follow you online. Rude. We know. That's why powerful tool stops them cold.
Faster Page Loading
By blocking some ads and scripts that bog down browsing, pages load up to 44% faster. Now that's a win-win.
Screenshots
Uncomplicate screenshots. Take and share them directly from the tool. That means no more searching for mysterious file names on your computer.
Pocket
Built right into the toolbar, it's the ultimate save-for-later feature. View your articles, videos and pages across any device.
Gaming & VR
Engineered for next-gen gaming, the browser has built-in support for WASM and WebVR. No additional installation needed!
Library
Save time! Find all your favorite content like Pocket saves, bookmarks, browsing history, screenshots and downloads in one spot.
Extensions
Customize the tool with thousands of extensions like LastPass, uBlock Origin, Evernote and more.
Themes
Make over the app to suit your mood! Choose a new look from theme categories or create your own.
Toolbar
Set up Fire fox your way. Drag and drop features in and out of your toolbar for easy access.
Sync your devices
Seamlessly access passwords, bookmarks and more. Plus, use Send Tabs feature to instantly share open tabs between desktop, mobile and tablet.
Also Available: Download Firefox for Windows

Displaying PDF files in a browser other than Safari requires you to have Adobe's Acrobat reader installed.
Acrobat Reader installs a plug-in for each browser it finds on your system.
So, if you install Acrobat Reader, then you will be able to view your PDF files.
Now, you also need to know that Adobe has not updated their software to be 'Universal' (compatible with Intel Macs).
This means that FireFox (and any other browser) will automatically disable PowerPC plug-ins while you are using them in Intel Native Mode. So, you will need to run FireFox in 'Rosetta' mode. This will enable the PowerPC plug-ins to work.
Here's a document explaining how to force a Universal program (such as FireFox) in Rosetta / PowerPC mode:
http://docs.info.apple.com/article.html?artnum=303120
So, run FireFox in Rosetta mode and Install Acrobat Reader (the latest version) and see if that works.
As for your other Adobe program, Adobe still has not updated it to run Natively on your Intel Mac, so that is likely part of your problem.
Let me know if you have other questions, or need further clarification on some of the details.
I hope this helps.

Mozilla Firefox for Mac is a fast, full-featured Web browser. The app includes pop-up blocking, tab-browsing, integrated Google, Yahoo and Bing search, simplified privacy controls, a streamlined browser window that shows you more of the page than any other browser and a number of additional features that work with you to help you get the most out of your time online.
Hide your real IP address and protect your privacy while online! Check out HMA! Pro VPN for Mac!
Check out the new Firefox for macOS, which is first of several releases called Firefox Quantum for Mac, getting you to the things you love and the stuff you need faster than ever before, along with a fresh new look.
Features and Highlights
2x Faster
Crazy powerful browser engine? Check. Less time waiting around for pages to load? Also, check. Get the best Firefox yet.
30% lighter than Chrome
Less memory usage means more space for your computer to keep running smoothly. Your other programs will thank you.
Smooth browsing
Whether you've opened 10 or 1000, switching between tabs is faster than ever with the program's new, responsive engine.
Private Browsing
The app blocks online trackers while you browse and won't remember your history after you're done.
Tracking Protection
Some ads have hidden trackers that follow you online. Rude. We know. That's why powerful tool stops them cold.
Faster Page Loading
By blocking some ads and scripts that bog down browsing, pages load up to 44% faster. Now that's a win-win.
Screenshots
Uncomplicate screenshots. Take and share them directly from the tool. That means no more searching for mysterious file names on your computer.
Pocket
Built right into the toolbar, it's the ultimate save-for-later feature. View your articles, videos and pages across any device.
Gaming & VR
Engineered for next-gen gaming, the browser has built-in support for WASM and WebVR. No additional installation needed!
Library
Save time! Find all your favorite content like Pocket saves, bookmarks, browsing history, screenshots and downloads in one spot.
Extensions
Customize the tool with thousands of extensions like LastPass, uBlock Origin, Evernote and more.
Themes
Make over the app to suit your mood! Choose a new look from theme categories or create your own.
Toolbar
Set up Fire fox your way. Drag and drop features in and out of your toolbar for easy access.
Sync your devices
Seamlessly access passwords, bookmarks and more. Plus, use Send Tabs feature to instantly share open tabs between desktop, mobile and tablet.
Also Available: Download Firefox for Windows

Displaying PDF files in a browser other than Safari requires you to have Adobe's Acrobat reader installed.
Acrobat Reader installs a plug-in for each browser it finds on your system.
So, if you install Acrobat Reader, then you will be able to view your PDF files.
Now, you also need to know that Adobe has not updated their software to be 'Universal' (compatible with Intel Macs).
This means that FireFox (and any other browser) will automatically disable PowerPC plug-ins while you are using them in Intel Native Mode. So, you will need to run FireFox in 'Rosetta' mode. This will enable the PowerPC plug-ins to work.
Here's a document explaining how to force a Universal program (such as FireFox) in Rosetta / PowerPC mode:
http://docs.info.apple.com/article.html?artnum=303120
So, run FireFox in Rosetta mode and Install Acrobat Reader (the latest version) and see if that works.
As for your other Adobe program, Adobe still has not updated it to run Natively on your Intel Mac, so that is likely part of your problem.
Let me know if you have other questions, or need further clarification on some of the details.
I hope this helps.