Beta
It has no Windows Alt code: copy it from this page, or use its HTML entity or Unicode number.
Copy it
About the beta
Beta comes from the Phoenician beth, the word for house, and with alpha it gave the alphabet its name. In 1899 Ernest Rutherford called the more penetrating of the two radiations he found coming from uranium beta rays.
The beta version of software is usually traced to IBM, which from at least the 1950s used A, B and C tests for its products; in time alpha meant the test before announcement and beta the test before general release.