Comparison Chart

Serial Port Monitor is divided into Standard, Professional and Company Editions. 

The difference you can see here: 

Number of computers per license1110
Any serial port software/hardware can be analyzedyesyesyes
Monitor any number of serial ports at onceyesyesyes
Supports all COM-port typesyesyesyes
Intercepts all data read from/written to COM portyesyesyes
Built-in searchyesyesyes
4 types of customizable monitoring visualizers for viewing and logging datayesyesyes
Incoming and outgoing data streams loggingyesyesyes
Tracing all serial input/output control codesyesyesyes
Copying all recorded data to clipboardyesyesyes
Saving, loading and exporting all monitored datayesyesyes
Full duplex modeyesyesyes
Unique stream filtering tools with presetsyesyesyes
Monitoring serial ports which are already in usenoyesyes
Sending/receiving data to/from any COM port (Advanced Send Dialog)noyesyes
The possibility to change COM port parameters from Advanced Send Dialognoyesyes