BrowserCheck, from security company Qualys, evaluates your installed plug-ins and lets you know if they need to be updated. It's identical in function to Mozilla's Plugin Check, although it appears to be far more limited in scope for now.
Qualys' BrowserCheck helpfully targets out-of-date plug-ins, and provides links to download updates. Oddly, the service takes a unique approach by requiring the user to install a Qualys add-on before it will scan for out-of-date plug-ins. This is likely to frustrate many users, especially in the face of Mozilla's service, which doesn't require an additional add-on and currently scans for more plug-ins than Qualys' does.
BrowserCheck's limitations are hard to brush off. It will only work with 32-bit versions of Internet Explorer 6, 7, and 8; Firefox 3.0 through the current stable version 3.6.6; and Google Chrome 4 and 5. Beta versions of those browsers, as well as other browsers such as Opera and Safari, are not supported yet. Qualys checks for fewer plug-ins, limited to Adobe Flash Player, Adobe Reader 5.x and above, Adobe Shockwave, Apple QuickTime, BEA Jrockit, Microsoft Silverlight, Windows Media Player, RealPlayer, Windows Presentation Foundation for Mozilla-based browsers, and the Windows OS support expiration.
It does let you know if your browser itself needs an update, and the add-on concept could prove useful down the road. Wolfgang Kandek, chief technology officer for Qualys, said in an interview last week that he wasn't sure how requiring an add-on would affect scan adoption. He did add, though, that there are plans to get involved in scheduling scans and other "deeper dive" scans that would require hooks into the browser that only an add-on can provide.
Although BrowserCheck's initial limitations may seem to some like missteps, Qualys isn't a neophyte to the security field. Qualys' services are used by more than 4,000 companies in 85 countries. The ability to push the service out to that many businesses alone has the potential to close off many threat vectors that might not get patched otherwise. Still, from the looks of BrowserCheck as it is now, Mozilla's service casts a wider net, and that's a key factor to preventing security breaches.