Adobe AIR (Adobe Integrated Runtime) is a runtime for building Internet-connected desktop applications with offine storage. It’s been available for Mac and Windows for a while, and now an alpha (non-feature complete) Linux version has been released. I tested it out in Ubuntu 8.04.
AIR requires a fairly recent Linux distribution, GNOME or KDE, and a RPM or Debian package management system. To get transparency effects, you need a compositing window manager such as Compiz or Metacity with compositing.
To install AIR you need to run Adobe’s installer. Download the installer: