At this point it seems clear that Mozilla has instructed its content writers to never mention version numbers in Firefox release announcements. The reason remains a mystery. Take yesterday’s announcement, for example. It begins “Today’s release of Firefox” – which makes it sound like Firefox is a new product.
Anyway… the mystery Firefox release yesterday was in fact version 52, which fixes at least twenty-eight security vulnerabilities. The new version also adds support for WebAssembly, which can dramatically improve the performance of web-based applications. Support for those annoying WiFi ‘captive portal’ hotspot login pages is improved in Firefox 52, and there are further improvements to the warnings you’ll see when you’re presented with a login form on an unencrypted connection.
Firefox 52 also removes almost all remaining support for the NPAPI plugin technology, with the lone exception being Flash, which means Silverlight, Java, Acrobat and other plugins that depend on NPAPI will no longer work. Support for the NPAPI version of Flash will apparently be removed in the next major Firefox release.