It is a project definition file for a Symbian OS Application's source code... The project definition file is a Symbian OS-specific text file that ends in .mmp and defines how to build the application using:
-> The CodeWarrior IDE (importing a project into the IDE)
-> Microsoft's Visual Studio 2003 and later (non-Express edition) having the carbide.vs plug-in for handling Symbian OS applications using Visual Studio
-> The CodeWarrior IDE (importing a project into the IDE)
-> Microsoft's Visual Studio 2003 and later (non-Express edition) having the carbide.vs plug-in for handling Symbian OS applications using Visual Studio