From the Maoist perspective, Marxism-Leninism-Maoism is an extension of Marxism-Leninism, that emerged via the study and application of the writings of Mao during the Chinese Revolution and what would be considered the "Maoist" period of China. These were put into practice by a collection of anti-revisionist revolutionary communist parties in the global south, such as Philippines, Turkey, and Peru. This is where Gonzalo comes in, because as leader of the Peruvian Communist Party he was the first to synthesize the term Marxism-Leninism-Maoism after the studying the successes of the Peruvian and other revolutionary movements (for pedants, note I said movements and not revolutions). This is what is meant when people say "Gonzalo founded MLM", basically the same way Stalin "founded" Marxism-Leninism.

There's also a messy history of the term because it has been used by proto-Maoists (like the Black Panther Party), Third Worldists (evolved out of proto-maoism), and MLs claiming ML-MZT as some sort of universal ideological development, not to mention the deviationist MLMs that call themselves MLMpM-GT.

MLM parties today are active in the global south, notably Philippines, India, Turkey, Nepal, Brazil, etc but there are adherents in the global north (usually where the stereotypes come from) that so far have seen little success.