InterBase is a popular database put out by Borland/Inprise. More information about InterBase is available at http://www.interbase.com/. Oh, by the way, InterBase just joined the open source movement!
Note: Full support for InterBase 6 was added in PHP 4.0.
This database uses a single quote (') character for escaping, a behavior similar to the Sybase database, add to your php.ini the following directive:
magic_quotes_sybase = On