Is there a single word for "not yet released because it is still being worked on"?

I am working on a quality assurance system where some procedures might be in a state where they haven't yet been released because they are currently being worked on. They may have also been a previous release of the document, and the document I am trying to describe is the one with changes to the previous release.

An analogy might be how you would refer to Mac OSX 10.8 Mountain Lion - it isn't yet released, because it is still being worked on.

I have been calling it unreleased but this to me sounds awkward and doesn't really describe the state.

Is there a word that I'm overlooking that describes this?

Solution 1:

I assume that "the document I am trying to describe is the one with changes to the previous release" means "the document I am trying to describe makes changes relative to the current release and is its successor".

Consider terms like next-generation, successor, in development, next-rev, pre-release, upcoming, and future or future version.

Solution 2:

Not a single word, but in the works is a common phrase in such situations:

being planned, worked on, or produced.

^NOAD

Solution 3:

When talking of technical development, we mostly use in the pipeline.

There is a new version, Mountain Lion in the pipeline.