Word for “product version that was scheduled to be released but never was, in favor of a better version”

Question

Let's say, DirectX 4.0 is never released; Microsoft launches DirectX 5.0 instead. So DirectX 4.0 is like a very special version of DirectX that is never made public for whatever reason.

Is there a word for an act like this (preferably a verb), or for an unreleased version of that kind (preferably a past participle)?

More generally, you have made a product, version 1.0. But you decide that it should stay unreleased. You make a better version 1.5 and release that one. Is there an apt word that describes (what happened to) version 1.0?

Answer 1

You might be looking for shelve:

to decide not to use something such as a plan or suggestion now, although you may use it later

or scrap:

to decide not to continue with something such as a plan or an event; to get rid of something

Answer 2

In the automotive world these are referred to as concept cars

Prototype almost works, but typically a prototype is an early version of something that is intended to be released to the public, while the proof-of-concept is really just for internal use and is never intended to be released.

Another option is to refer to these as in-house products. Many companies will develop in-house, proprietary, tools that they use themselves but never intend to sell.

Answer 3

If it was a good thing, you'd probably say the earlier version was superseded before it could be released. To be more precise, it stayed in-house, remained experimental or under development, never shipped, never released, never made it past beta or alpha, etc.

To paint it negatively, you'd probably say the first version was vaporware.