Regarding database availability:

In addition to MySQL and PostgreSQL, upstream Roundcubemail includes support
for SQLite.  This has been disabled in the Fedora version (for the time being)
because Roundcube requires the SQLite2-compatible mainline PHP SQLite extension.
This extension is unavailable in Fedora in favor of the SQLite3-compatible PDO
SQLite extension (php-pdo package).  For this reason, we have disabled SQLite
support in Roundcube.  If upstream releases a new version that supports the 
PDO extension, or if SQLite2 support for PHP becomes available in Fedora, we
will re-enable SQLite support in Roundcubemail.

Jon Ciesla
05/11/2007

Additional installation information:

In your installation process, you'll need to modify db.inc.php and main.inc.php.  
In Fedora, these are located in /etc/roundcubemail.  These will work in this location,
and should not be moved.  They will not be modified at upgrade, so you may want to 
check the .rpmnew files at that time so see if you need to migrate your settings to 
the new file.

Jon Ciesla
10/20/2009