You need to run MCL Client to use an application developed by MCL Desginer for MT2000 for that scanner. MCL Client interprets MCL code of the application.
Symbol MT2070 barcode scanners have MCL Client pre-installed and pre-licensed within its factory default settings. Thus, except of a specific MCL application no additional MCL license is needed. On the other hand Symbol MT2090 barcode scanners have MCL Client only pre-installed but not pre-licensed. To run an MCL application on them you have to buy also MCL Client license for each MT2090 scanner.
Data transmission is maintained usually through MCL Link Lite V3 for MT2000 or MCL Link V3. While MCL Link Lite is a free utility and can utilize only limited number of communication ports MCL Link is a licensed software and offers full communication capabilities for batch data transfer between MT2000 and PC.