As part of a project to wipe out plug-ins from Chrome, Google blocked plug-ins from appearing in Chrome Web Store search results, category pages, and its home page on Tuesday.
Google said in a blog post that the multi-year plan will make Chrome a faster and more secure Web browser by eliminating security and instability problems that the Netscape plug-in application programming interface (NPAPI) add-ons, commonly called plug-ins, can introduce to Chrome. The list of popular plug-ins scheduled to get the axe includes Microsoft Silverlight, Java, the Unity game-building plug-in, and even Google's own Google Earth.
"Over the last few quarters, we've been encouraged to see an overall 12.9 percent drop in per-user instantiations of NPAPI plug-ins and declining usage of the most popular NPAPI plug-ins," wrote Chrome engineer Justin Schuh.
The move is the latest step in removing the NPAPI plug-ins, relics of an older browser development era. NPAPI plug-ins can be the source of problems in the browser because they are given access to lower-level, more critical browser code, but are rarely updated as often as the browser itself. This conflict can introduce security and stability problems.
"We are actively helping still-popular NPAPI-based services migrate to open-Web-based alternatives," Schuh said. Google has built a NPAPI deprecation guide to help developers with the transition. Google first announced its intentions to kill off NPAPI support in Chrome last September.
Adobe's Flash Player will not be affected, since the browser ships with a version of Flash built for Pepper (PPAPI), Google's custom browser plug-in architecture. The company also advises developers to use Native Client (NaCl) when possible. The pairing, NaCl (also the chemical shorthand for salt) and Pepper, might be too much Google spice for developers, since they are currently only supported by Chrome -- and no other browsers.
Further deprecation of NPAPI support is already in the pipeline. Chrome 37, currently available on the browser's developer's channel, will block browsers from installing NPAPI plug-ins with a "harder-to-bypass page-action blocking UI," and NPAPI support has been removed in Chrome 35 for Linux.
Since September, NPAPI plug-in usage has been on the decline, Google reports. Silverlight usage has dropped from 15 percent to 13.3 percent; Google Earth from 9.1 percent to 0.1 percent; Unity from 9.1 percent to 3.1 percent; Java from 8.9 percent to 7.2 percent; and Facebook from 6 percent to 4.2 percent. Google Talk usage remains unchanged, at 8.7 percent.