Host Admiral is a free web hosting control panel.
You can try on-line demo.
The main feature and the main difference from other control panels: it's not a complete system installation, it's a web interface to any existing mail/web/etc system. It doesn't implement any functions specific for some MTA or httpd, it just implements common "mail" and "web server" functionality. So it's up to system administrator to write a set of shell scripts to connect the control panel with the existing system. Some program specific things will be added only if there is no common standard for them.
The panel is not aimed to simplify web hosting for "dummies", its main target is to separate users privileges where operation system itself is not fine grained, e.g. to allow some users create new email addresses in its own domain only and not allow even to see any information about other users or domains. So, well-known features of control panels "password protected directories" (should be implemented e.g. with .htaccess in Apache), "file manager" (is business of FTP or scp), "schedule tasks" (cron & shell) will NOT be implemented; at least at this first step.
Main target platform for the project is: FreeBDS 5.x, Postfix 2.1.x, Apache 2.x, Tomcat 5.0.x, BIND 9. But I'm trying to make it configurable to be useable with any other programs.
Features to implement, sorted by priority:
Public domain - you are allowed to use it in any way.
The project is available as source code via Subversion repository or for on-line view. Subversion URL is https://www.26th.net/svn/general/hostadmiral/trunk/
The program is provided AS IS without any warranty. I do not promise anything about it.
But nevertheless if you found a bug or require some very good feature - please submit it to bugzilla.
If you have some questions or problems with the program - ask me per email.
Once again - no warranty.