alpha version

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A development status that usually means an early version of a program or application, that is most likely unstable, but is useful to show what the product will do to, usually, a selected group. Sometimes this stage is referred to as a preview version. Sometimes no more features are added after this release, but bug fixes continue. This release comes after a pre-alpha version and before a beta version. As opposed to a beta version an alpha version is usually not feature complete.