Owen Taylor has been rocking recently. In the 0.3.x releases there’s an optional packagekit-plugin package that is a standard Mozilla plugin. It works in Firefox and Epiphany and looks something like this:
Test page shipped with PackageKit
It’s actually pretty easy to build a website that wants to install something new or run an application that is already installed.
The actual html you need is something like this:
<object type="application/x-packagekit-plugin" width="500" height="200" class="packagekit-plugin">
<param name="displayname" value="KStars"/>
<param name="packagenames" value="kdeedu kde4edu"/>
<param name="desktopnames" value="kstars"/>
You can omit displayname and desktopnames if you wish, as PackageKit can query the backend and fill in the blanks. The packagenames are queried until PackageKit finds one that matches on your system.
I’m also thinking about adding the application icon in the box as common applications usually have standard icons that PackageKit already uses for other stuff.