Microbial enzymes can come from bacteria, actinomycetes, fungi, yeast, microalgae, and cyanobacteria. The class of extremophile microorganisms is a source of interesting enzymes that can overcome various technological problems. Globally, these enzymes are industrially produced by fermentation using two techniques: submerged fermentation (SmF) and Solid-State Fermentation (SSF). Currently, microbial enzymes are probably the most important sector in biotechnology. This field finds different applications in various industrial sectors including chemical and pharmaceutical, food and animal feed, textile, agriculture, biodiesel, and so on. The present review surveys the microbial enzymes and their major characteristics, safety, chemical nature and classification, microbial sources of enzymes, production aspects, biotechnological applications, commercial overview, and perspectives and future prospects.