Mozilla, an open source organization whose Firefox Web browser operates in a highly competitive market, is extending a security service for plugin checking to users of rival browsers.

The Mozilla plugin checker is an online service that first debuted for Firefox users in October 2009. Firefox 3.6 also provides an integrated mechanism enabling users to check their plugin status.

The technology now also works for Apple's (NASDAQ: AAPL) Safari 4, Opera 10.5 and Google's (NADSAQ: GOOG) Chrome 4, as well as Internet Explorer 7 and 8. The plugin checker provides users with a service that helps to identify whether the plugins on their systems are up-to-date.

Running out-of-date plugins often poses a security risk. Security researchers have noted in the past that out-of-date Flash plugins could potentially be leaving the Web at risk, for instance.

Out-of-date plugins for Adobe Flash, Shockware, Quicktime and Java are among the items Mozilla's service checks, though not all plugins are checked for IE.

A Mozilla spokesperson explained in an e-mail to that Internet Explorer requires a different markup for each plugin, so it takes a little longer to write each specific code.

It's also not entirely clear how consistent the current plugin checker is at identifying plugins. In a test conducted by on the Mozilla plugin checker, the service did not identify any of the Flash plugins used on a fully patched Windows XP SP3 machine running Internet Explorer 8. The spokesperson said that Mozilla has not seen or heard of this issue. has provided Mozilla with a screenshot of the test in an effort to help fix the issue.

While the plugin checker effort benefits users of the Opera, Apple, Google and Microsoft browsers, those vendors did not work with Mozilla on the effort. According to the Mozilla spokesperson, the plugin checker effort was developed in-house.

However, Mozilla is looking to get some assistance from plugin vendors in an effort to help maintain and grow the checker service.

"It would be especially helpful for plugin vendors to let us know as new versions are released and old versions become vulnerable to security threats so we can keep the checker as up-to-date as possible," the spokesperson said.

Sean Michael Kerner is a senior editor at, the news service of, the network for technology professionals.