Betamax (also called Beta, and referred to as such in the logo) is a consumer-level analog videocassette magnetic tape recording format developed by Sony, released in Japan on May 10, 1975. The cassettes contain -wide videotape in a design similar to the earlier, professional wide, U-matic format.

From Betamax to Blockbuster
From Betamax to Blockbuster:Video Stores and the Invention of Movies on Video
From Betamax to Blockbuster: video stores and the invention of movies on video
Modernizing Sony-Betamax for the Digital Age: The Ninth Circuit Enables P2P
The Economics of Betamax: Unauthorized Copying of Advertising Based Television Broadcasts
The fall of a Silicon Valley icon: Was Apple really Betamax redux?
Why Blu-Ray vs. HD-DVD is Not VHS vs. Betamax: The Co-Evolution of Standard-Setting Consortia
The Parody Defense to Copyright Infringement: Productive Fair Use after "Betamax"
Fair Use as Market Failure: A Structural and Economic Analysis of the "Betamax"Case and Its Predecessors
Eradication of introduced signal crayfish Pasifastacus leniusculus using the pharmaceutical BETAMAX VET.?.