As outlined in the NPAPI Deprecation Guide, Chrome 42, which was due this month and was recently released to the stable channel, has disabled support for the Netscape Plug-in API. The reason is that NPAPI “has become a leading cause of hangs, crashes, security incidents, and code complexity” and the intent was first announced in 2013.

NPAPI plug-ins were blocked since January 2014, but some of the popular ones were whitelisted, including Java, Unity, Silverlight, Facebook Video, and a couple of others. In January 2015, the respective plug-ins were blocked by default, but the user could enable them for specific websites. Now, the NPAPI itself is disabled, and the plug-ins using it no longer appear on the chrome://plugins/ page.

Mac OS and Windows users can enable NPAPI through its flag on the chrome://flags/ page, and enterprise administrators are still able to whitelist related plug-ins through the EnabledPlugins policy list. This solution will work until September when support for NPAPI will be completely removed from Chrome.

NPAPI is still used by several Mozilla projects, including Firefox, and Apple’s Safari. Nonetheless, Mozilla mentions on their developer site that “plug-ins are now a legacy technology” and advises website developers to “avoid using plugins wherever possible”.

We have not heard of any plans from Oracle or Microsoft intending to port their plug-ins to use Chrome’s Native Client.

Update. After the publishing of this article, Oracle has provided instructions on using Java on Chrome 42. Among others, they suggest switching to Firefox, IE or Safari. No word on porting the Java plug-in to use the Native Client.