The most recent version of the Xen Shell is version v1.9, and you can download it via the following link:
Binary packages of the project are included in the Debian GNU/Linux Project, in both the Unstable and Testing branches.
I maintain a package for Debian stable upon my personal apt repository.
If you're using this tool commercially I'd love to hear from you, just drop me a mail.
A donation is always nice from commericial users but not mandatory! I'm just very interested in seeing who is using the software in production- it would be nice to have links to any hosting companies, etc, who are offering it to their clients.
Of course if you have feedback, suggestions for new commands and facilities it would be great to hear those too :)
There is a Debian binary package which is available from my apt-get repository for the Etch release of Debian GNU/Linux. If you're using the unstable/sid branch it should be available in the official Debian repository, thanks to Radu Spineanu.
Note: you will need to configure sudo, as described in the README file.
A Debian package could be made available if there is any interest?