The only significant differences between EMS Manager, Fire Manager and Zanager are cosmetic.
All three systems are built on the same code base and all share the same basic functionality. However, each system has a different look and feel and each system has its default settings and demo configuration customized to best fit its niche.
Our first scheduling system was built in 2002, and we called it EMS Manager. In 2008 Fire Manager was added, and in 2011 we added Zanager. The code base is constantly being enhanced and improved based on the thousands of discussions we've had with users over the years.