Programs / modules for the cms system. your extension place
Programs are your path to include projects eg.:
Mumsys/Programs/Newsletter or
Mumsys/Programs/Stats
Mumsys/Programs/Demo
which means in detail:
Mumsys/Programs/Demo/
Mumsys/Programs/Demo/Models/
Mumsys/Programs/Demo/Views_or_Templates/
Mumsys/Programs/Demo/Controllers/