What Is Growl?

Please review http://www.theatremanagerhelp.com/frequently-asked-questions/version900 it talks about Growl with the following information:

We have integrated Growl Notification into Theatre Manager so that meeting reminders, task alarms and some system notifications will show a passive window that appears for a few seconds and then fades away. This feature can be enabled and disabled on a per employee basis. Notifications will still appear in the notification window. The purpose of growl is to allow the notification window to get buried, yet the user will receive a small hint that there is something significant to deal with.

If you are being asked to upgrade Growl on your machine to a newer version, is it ok to upgrade it without harming Theatre Manager.