All files can be downloaded under https://sourceforge.net/projects/globalplatform/files/
There are prebuild version available for Windows, Ubuntu/Debian and Fedora.
There is a Launchpad PPA for Ubuntu and Debian under GlobalPlatform PPA.
Just uncollapse Technical details about this PPA and add this to your Software Sources/Repositories under Ubuntu or follow the steps under Read about installing.
For Ubuntu Oneiric the two lines for the Software Sources are:
deb http://ppa.launchpad.net/k-o-/globalplatform/ubuntu oneiric main deb-src http://ppa.launchpad.net/k-o-/globalplatform/ubuntu oneiric main
You have to replace oneiric with your Ubuntu or Debian version name.
For Debian Squeeze this should be:
deb http://ppa.launchpad.net/k-o-/globalplatform/ubuntu squeeze main deb-src http://ppa.launchpad.net/k-o-/globalplatform/ubuntu squeeze main
For developing with the GlobalPlatform Library you must also install the Development packages.
There are prebuild files under https://sourceforge.net/projects/globalplatform/files/. Take the latest GPShell version to get all.
You must unzip the file into a directory and change into this directory to run GPShell.
Under Fedora you can execute the following line to get all packages:
yum install gpshell