Getting into gear

Google has launched “Google Gears” – an open source browser extension that lets developers create web applications that can run offline.


US search engine behemoth Google has launched what it’s calling “Google Gears”  – an open source browser extension that lets developers create web applications that can run offline.


The Gears software provides developers with three key features. First off, there’s a local server to cache and serve application resources (HTML, JavaScript, images, etc.) without needing to contact a server. Then, there’s a database so that data can be stored and accessed  from within the browser. Lastly, there’s a worker thread pool, to make web applications more responsive by performing expensive operations in the background.


There are generally two ways to use Google Gears: by embedding the API or runtime software in an application that a developer distributes to end users, or by writing a web application which makes use of installations of Gears on end-users’ computers.


A BSD license allows developers to embed the Google Gears runtime or API in their software with very minimal restrictions. There are no restrictions on web applications which make use of Google Gears installations on users’ computers.


At the moment, Google Gears works on the following browsers:



  • Apple Mac OS X (10.2 or higher)
              Firefox 1.5 or higher
  • Linux
              Firefox 1.5 or higher
  • Microsoft Windows (XP or higher)
              Firefox 1.5 or higher
              Internet Explorer 6 or higher

Additionally, the Google team is working on supporting Safari on Mac OS X in a future release.


Google Gears is currently an early-access developers’ release and it’s not yet intended for use by real users in production applications at this time.


A Gears Tutorial is available here that illustrates the basic concepts.