The minimal requirement is a working JDK5 installation. Griffon comes with its own version of Groovy bundled in. However it is preferred that you use JDK6 as there are multiple improvements on the desktop APIs and its performance.
Installing Griffon is as easy as:
1. download the latest stable distribution from http://griffon.codehaus.org 2. unpack the .zip file (or .tgz) into a directory of your choosing, ie, /opt/griffon
3. add an environment variable name GRIFFON_HOME that points to /opt/griffon
4. make sure $GRIFFON_HOME/bin is added to your PATH variable
You can also install Griffon using the universal installer. It will take care of setting up the paths for you.