Self Service Password Reset ships as part of Identity Manager and you install it with the integrated installer. All of the releases of Self Service Password Reset have not synchronized with the Identity Manager release.
The Identity Manager integrated installers installs Tomcat for you. Self Service Password Reset supports the version of Tomcat installed with the integrated installer if you use the integrated installer to install Self Service Password Reset. If you install Self Service Password Reset as a standalone deployment, you must meet the Self Service Password Reset requirements. For more information, see Installing Self Service Password Reset
in the Self Service Password Reset 4.4 Installation Guide.