Callicore has two components, a web application framework and a PHP-GTK2 baseddesktop framework application. Although currently there are no public releases of any of the callicore code, the source is available via subversion. Callicore is designed for php 5.2, but currently still works with 5.1.x. This may change in the future.
Callicore has two mailing lists, one to keep track of svn commits and a developer list for those wishing to get involved with the callicore project
Currently two items are under active development. Callicore Desktop is the PHP-GTK2 framework half of Callicore. A simple program using CC as its base, Writer, is also available via svn. There is no current timeline for an alpha release but several items in CC Desktop are completed. If you'd like to be involved with any aspect of the project, or want to ask questions, submit bugs, or ask for features please join the development mailing list above and speak up.