The mParticles toolset is designed to extend the power and flexibility of the standard Particle Flow system, particularly in its abilities to create sophisticated, realistic physics simulations.
Taking advantage of the powerful MassFX simulation engine included with 3ds Max, the mParticles system provides operators and tests to replicate real-world effects such as natural and man-made forces, binding particles together and then breaking the bonds, collisions between particles and with other objects, and more. Also included are several new Birth operators that are optimized for physics simulations as well as a preset flow that makes initial setup a snap. To top it all off, mParticles gives you three easy-to-use modifiers that allow particles to affect standard mesh objects in mind-blowing ways.
For a tutorial about mParticles, see mParticles Quick Start Tutorial.