Background
FireWatir has a similar API to Watir, though accesses the DOM by invoking JavaScript by using the JSSh XPI to telnet into the browser. FireWatir is compatible with Firefox 1.5 and above: running on Windows, OSX and GNU\Linux.
There is an ongoing merge of FireWatir and Watir; intially through running the Watir unit tests against FireWatir and eventually merging the code-bases.
Installation
Installation is simple. See the latest installation guide for details.
Example Script and TroubleShooting
Compatibility between FireWatir and Watir
Our ultimate aim is to have full compatibility between FireWatir and Watir scripts. In the meantime there is a list of known compatibility issues.
Release Notes
FireWatir Release Notes
FireWatir Compatibility
Development Notes
You can find a list of FireWatir contributors on the Watir Contributors page.
The FireWatir Compatibility page is currently being updated by Lawrence Nuanez.