Migration Agent is a set of simple programs or/and scripts intended for collecting information from the source system in a strictly defined XML form (XML documents).
Migration Agents are separated by the type of operating system. Linux-based migration agents are implemented as the command-line tools and MM communicates with such agent via SSH protocol. Windows-based migration agents are implemented as .NET dynamically-loaded libraries ("assemblies") and MM uses SOAP over HTTP to communicate with them.
For more information, refer to the Migration Agents Development section.