Firefox 52.0 (64-bit)

What's new in this version:

New
- Added support for WebAssembly, an emerging standard that brings near-native performance to Web-based games, apps, and software libraries without the use of plugins
- Added automatic captive portal detection, for easier access to Wi-Fi hotspots; when accessing the Internet via a captive portal, Firefox will alert users and open the portal login page in a new tab
- Added user warnings for non-secure HTTP pages with logins; firefox now displays a “This connection is not secure” message when users click into the username and password fields on pages that don’t use HTTPS
- Implemented the Strict Secure Cookies specification which forbids insecure HTTP sites from setting cookies with the "secure" attribute; in some cases, this will prevent an insecure site from setting a cookie with the same name as an existing "secure" cookie from the same base domain
- Enhanced Sync to allow users to send and open tabs from one device to another

Fixed
- Various security fixes
- Improved text input for third-party keyboard layouts on Windows; this will address some keyboard layouts that: have chained dead keys, input two or more characters with a non-printable key or a dead key sequence, input a character even when a dead key sequence failed to compose a character

Changed
- Removed support for Netscape Plugin API (NPAPI) plugins other than Flash; silverlight, Java, Acrobat and the like are no longer supported
- Removed Battery Status API to reduce fingerprinting of users by trackers
- Improved experience for downloads: Notification in the toolbar when a download fails, Quick access to five most recent downloads rather than three, Larger buttons for canceling and restarting downloads
- Display (but allow users to override) an “Untrusted Connection” error when encountering SHA-1 certificates that chain up to a root certificate included in Mozilla’s CA Certificate Program; (Note: Firefox continues to permit SHA-1 certificates that chain to manually imported root certificates.) Read more about the Mozilla Security Team’s plans to deprecate SHA-1
- Migrated Firefox users on Windows XP and Windows Vista operating systems to the extended support release (ESR) version of Firefox
- When not using Direct2D on Windows, Skia is used for content rendering

Developer
- Enabled CSS Grid Layout, opening up a world of new possibilities for graphic design
- Redesigned Responsive Design Mode to include device selection, network throttling, and more
- Improved security for screen sharing, which now shows a preview and no longer requires a whitelisted domain

Unresolved
- Google Hangouts temporarily won't work