Recently Mozilla introduced Jetpack, a Firefox add-on that makes it possible to post-process webpages within the web browser. For the non-techies out there, this means that one can now create small software programs that, if installed, can alter a webpages content by changing, adding or removing parts of it before it is displayed on your computer screen.

For the more technically minded, this post-processing of web pages is made possible because JetPack plugins have access to the Document Object Model (DOM). Since the DOM describes the structure and content of a web page, the software can manipulate the webpage’s content after the page is received from the web server but before it is displayed to the user. As a result static web pages, even the ones you do not control, can become dynamic mashups.

This may seem insignificant but it has dramatic implications. For example, imagine a JetPack plugin that overlays a website – say of BarrackObama.com or FoxNews.com – that causes text bubbles that counterspin a story when your mouse hovers over it. The next republican nominee could encourage supporters to download such a hypothetical plugin and then direct their supporters to Obama’s website where each story could be re-spun and links to donating money to the republican campaign could be proffered. They would, in short, dynamically use Obama’s webpage and content as a way to generate money and support. TPM could create a similar Jetpack plugin for the FoxNews website which would do something similar to the title and body text of articles that were false or misleading.

Such plugins would have a dramatic impact on the web experience. First, they would lower costs for staying informed. Being informed would cease to be a matter of spending time searching for alternative sources, but a matter of installing the appropriate JetPack plugin. Second, every site would now be “hijackable” in that, with the right plugin a community could evolve that would alter its content without the permission of the site owner/author. On the flip side, it could also provide site owners with powerful community engagement tools: think open source editing of newspapers, open source editing of magazines, open source editing of television channels.

The ultimate conclusion however is that JetPack continues to tilt power away from the website creators to viewers. Webpage owners will have still less control over how their websites get viewed, used and understood. Effectively anyone who can persuade people to download their JetPack plugin can reappropriate a website – be it BarrackObama.com, FoxNews.com, eBay, or even little old eaves.ca – for their own purposes without the permission of the website owner. How the web eco-system and website developers in particular react to this loss of control will be interesting. Such speculation is difficult. Perhaps there will be no reaction. But one threat is that certain websites place content within proprietary systems like Flash where it would be more difficult for JetPack to alter their contents. More difficult to imagine, but worth discussion, is that some sites might simply not permit Firefox browsers to view their site.

In the interim three obstacles need to be overcome before JetPack realizes its full potential. Currently, only a relatively small community of technically minded people can develop JetPack add-ons. However, once Jetpack becomes an integral part of the Firefox browser this community will grow. Second, at present installing a JetPack plugin triggers a stern security warning that will likely scare many casual users away. Mozilla has hinted at developing a trusted friends system to help users determining whether a plug-in is safe. Such trust systems will probably be necessary to make JetPack a mainstream technology. If such a community can be built, and a system for sorting out trusted and untrustworthy plugins can be developed, then Jetpack might redefine our web experience.

We are in for some interesting times with the launch of Firefox 3.5 and new technologies like JetPack around the corner!

Jetpack is available at jetpack.mozillalabs.com

Diederik van Liere helped write this post and likes to think the world is one big network.