  Magnetic Penrose process (MPP) is not only the most exciting and fascinating
process mining the rotational energy of black hole but it is also the favored
astrophysically viable mechanism for high energy sources and phenomena. It
operates in three regimes of efficiency, namely low, moderate and ultra,
depending on the magnetization and charging of spinning black holes in
astrophysical setting. In this paper, we revisit MPP with a comprehensive
discussion of its physics in different regimes, and compare its operation with
other competing mechanisms. We show that MPP could in principle foot the bill
for powering engine of such phenomena as ultra-high-energy cosmic rays,
relativistic jets, fast radio bursts, quasars, AGNs, etc. Further, it also
leads to a number of important observable predictions. All this beautifully
bears out the promise of a new vista of energy powerhouse heralded by Roger
Penrose half a century ago through this process, and it has today risen in its
magnetically empowered version of mid 1980s from a purely thought experiment of
academic interest to a realistic powering mechanism for various high-energy
astrophysical phenomena.
