After an initial round of in-house testing, software publishers often release new programs to be tested by the public. These pre-release versions are called beta software, usually denoted by a "b" in the version number, e.g., Netscape Navigator 2.0b5. Since the publisher couldn't possibly test the software under all possible conditions, it is reasonable to expect that wider use of the software may uncover problems that were not discovered during in-house testing. The publisher expects to be notified when users find such problems so that the program can be fixed before its official release.

In general, you should expect to run into bugs whenever using any piece of beta software. These bugs may range in severity from minor features that don't work to problems that cause your computer to crash. You should decide whether the benefit of new features in a beta program outweighs the risk of program instability before choosing to use a piece of beta software. You should also be aware that UITS will not have thoroughly tested beta software, nor will the software be guaranteed by its maker, so you should not expect the same level of support as you would receive for an official release version of the program.