History
MODBUS® is an industrial protocol originally developed by the Programable Logic Computer (PLC) manufacturer Modicon in the late 1970's. Still, thirty years later, MODBUS® is still one of the most common protocols in industy and is offered as a communications option by most hardware / software vendors.
The MODBUS® framework for Cocoa has been developed and is offered under GNU Library General Public License to spur on continued devleopment in Cocoa for the Mac OS X operating system.
MODBUS® is a registered trademark of Modbus Organization, Inc.

ModBusApps
Control engineers and instrumentation technicians require software tools to test communications both to and from Programmable Logic Controllers (PLCs), Remote Terminal Units (RTUs), and other logic solving devices. There are a number of software tools available for the Microsoft Windows operating system, but there has been relatively little industrial development on the Apple Mac OS X operating system.
ModBusProbe has been developed by Matthew Butch of Volitans Software and Rudy Boonstra of R Engineering Inc. to provide one of the necessary tools to use the Apple Mac OS X platform for industrial control. Additionally, the framework ModBusKit was released to encourage further software development.