JCal Pro® (versions 1.5 and 2 for Joomal 1.5.x) requires the following system specifications**:
- PHP 5.2+
- MySQL 4.1+
- Joomla 1.5.15+
Additional parameters typical in most hosted server environments are not listed.
** The PHP and MySQL requirements for JCal Pro® match those recommended for Joomla itself (Joomla's minimum requirements are not sufficient).