Second letter of the
Greek alphabet.
In software development, "beta version" refers to a product that is not fully debugged or fully functional but satisfies a majority of the requirements. Beta versions (or just betas) are an intermediate step of the full development cycle. They are released to a group of beta testers (or, sometimes, to the general public) for a user test. The testers report any bugs that they found, features they would like to see in the final version, etc. When a beta is released to the general public it often becomes used almost as widely as the finished product is (when the product is completed.) Usually freeware or open-source betas are released to the general public while proprietary betas are released to a relatively small group of testers.