I've been coming across this term too much recently. But I'm not sure what it is. I know about Alpha testing and Beta testing. I know the version of the application made available to users for and during beta testing is called a Beta release. But what exactly is Pre-beta? If they are releasing it to public for testing, it's already Beta, right?
Pre-beta sounds like a non-standard term that people are inventing.
The common term for pre-beta is an alpha release, hence beta being the greek alphabet letter that comes after alpha.
Microsoft use the term "Technology Preview" that essentially means not of beta quality and features may change but hey, have a look and tell us what you think.
BETA releases generally refer to full functionality and minor-no bugs expected. Pre-BETA releases are generally considered not as stable as their Beta counterparts. Some features may not be implemented and it would not be surprising to the developers to experience a Blocker issue and/or major bugs.
BETA = minor tweaking needed Pre-BETA = major development still needed
Alpha: Internal user base, development still in progress, all features fully not ready. Testing continues in parallel.
Beta: External user base, all features ready but extended to friendly customers to expose it to more people for identification of more defects outside testing environment as majority of the cases Beta is conducted on Production environment.
Pre - Beta: Few companies use it even if it is not a formal term coined by test standards but what I have encountered in few companies and projects mean the below.
An intermediate stage that does not last more than few weeks where for some reason example a) all trialists have not been recruited b) Beta trials date have been delayed due to identification of defects but the code is ready for majority of the functional features Pre Beta is considered as an option as a mitigation plan. This is primarily done for 2 reasons 1) if there are any contractual obligations to hit any particular dates and make the code accessible to third party vendors for integration purposes on Production environment or 2) There are particular scalability/operational items that needs to be validated and can be done only on Production. This trial base provides the perfect condition as the number of trialists are more than Alpha base but lesser than Beta (which also consists of paid customers).