Homeseer home automation software has been around for a long time. Bob's Place Media Engineering originally developed a plug-in to interface Homeseer HS2 with the Universal Devices Inc. ISY controller. This allowed Homeseer to see and control any Insteon devices, Z-Wave devices, programs, network resources and variables in the ISY controller.
When Homeseer release HS3, the plug-in was re-written to support HS3. The WeatherFlow and RainMachine plug-ins were added later.
When Homeseer released HS4, the effort to re-write the plug-ins yet again was too great. The above three plugins remain available as Legacy plug-in and continue to work in HS4.