Mozilla Firefox 38 is a web browser developed by Mozilla Foundation , available for download in full install version for Windows platforms from legacy sources. This version of Firefox was officially released on 2015-05-12 for public access and a brief summary of important updates and change log pertaining to this edition can be read below.

Firefox 38 is released with few changes and usual security fixes. One noticeable addition to this version is support for Ruby Annotation which would be mostly useful for Japanese & Chinese websites where the additional text on top of usual text is readable now.

In the optimization part, Mozilla now improved page load time via speculative connection warm up. In the user interface improvements side new tab based preference has been introduced. One key change of inability to block auto complete for username/password might  make some users uncomfortable. 

In the HTML5 additions, support for Encrypted Media Extension API would make HTML5 audio Video playback for Windows Vista and later OSs. In OS X editions now HTML5 native playback is available.