
I will introduce a "democratic neutrino" theory based on very simple Lagrangian that describes three Majorana neutrinos, two of which have equal masses. This theory has only one free parameter in contrast to 7 (9) free parameters in the conventional model of Dirac (Majorana) neutrino masses and mixing. Surprisingly, taking into account the incoherence and matter effects, this democratic theory agrees with the Super-Kamiokande and the Sudbury Neutrino Observatory results on atmospheric and solar neutrinos, respectively. I will discuss the predictions of this theory for low energy beta decays, magnetic moments, and neutrinoless double beta decay experiments. I will also introduce a recent research on nonstandard neutrino interactions.