International Organization for Standardization, responsible for defining characteristics of quality regimes (manufacturing and services), and an environmental protection regime.
The organization’s website states that ISO is not an acronym of the organization’s name in any language (and note that the organization’s name in English is not “International Standards Organization”). Instead, “iso” comes from the Greek word “isos,” which means “equal.” Equal to what? They don’t say.
Acronym pronounced by spelling it out.