I don't understand your question.
You don't extract any ESM files. By PC I assume you mean Windows PC. If you don't have a Windows installation, you can extract the Morrowind installer with "innoextract" or install it with Wine.

I was under the impression OpenMW only needed the ESM files to run? Either way I will try innoextract or Wine. Thanks.

Oh, now I get what you meant. Normally, people talk about extracting an archive when talking about extracting the files in the archive would actually make more sense. You don't only need ESMs though, but almost everything apart from the EXE file.

A new version has been released: OpenMW 0.41

A new version has been released: OpenMW 0.42

A new version has been released: OpenMW 0.43

What, currently, from the perspective of the end user, is the difference between Morrowind (with nodding) and OpenMW?

The way the release notes are phrased, it seems that the only difference right now is that shadows aren't implemented in OpenMW?

Openmw is reimplementation of orig engine, so main feature before 1.0 is portability on other platforms and fixing of annoying vanilla's bugs. Open source code allowed to add multiplayer capability

A new version has been released: OpenMW 0.45

The PPAs still show 0.44 tho. Maybe we need to wait a few days.

https://launchpad.net/~openmw/+archive/ubuntu/openmw

EDIT2: The new update available now. I tested it and it introduces some very nice features.

A new version has been released: OpenMW 0.46

A new version has been released: OpenMW 0.47