Before its final commercial release, a(n) version of software may be offered to certain test sites or to interested users free or at a reduced cost

beta version of software

Explanation:

The beta version of a software is the first release of the software that is not regarded as the final release usually given to a large number of people to use under real conditions. This version of software undergoes alpha testing before they are sent out to user and are usually almost a close-double of the final product in appearance, function, and feel. Nonetheless, changes in design are usually performed before releasing the final version.

this seems to be in the wrong category. but i'll take some free points my dude

posting this in wrong category will result in people seeing it who won't know the answer.