alpha and beta release, also called pre-releases, usually come with even fewer guarrantees of worthiness than exist in officially released software. Usually alpha and beta releases of a program are free with the agreement that any bugs found by the user will be reported to the producer.

Despite the movement towards mathematically provable software, there is a realization among most developers that when a system is 'sufficiently complex', they can't reasonably test all of the possible things that could go wrong. And so they release it to the general public - or those among them who are willing to undergo a bit of risk.

Usually the risk is not that great. Software breaks. Reboot required. In some very rare cases, there might be gradual corruption of databases in a way that cannot be readily detected until well after the last good backups have been overwritten. Well, that's the potential anyway - but I've never seen or known it to occur. Usually when beta stuff breaks, it's not even a nuisance.

I used to get daily irritated with MS until I just learned to think of every version of their OS as being alpha, even though I payed for the software. It has the reliability and security of most other alpha software that I'm familiar with.