"Preview 2" is the tooling version (command line tools). The tools (such as the dotnet command and related binaries) are versioned separately from the framework itself.

This allows the team the ability to release new tooling versions (bugfix to the donet command for example), without having to print a new framework version. Same for updating the framework vs the tooling.

On the one hand, it's annoying to keep track of so many versions. On the other hand, it's also annoying to be forced to run a framework update when the only thing that's changed is a command line tool, which may or may not be important to a specific organizations development pipeline.

Thanks for the explanation, makes sense.

Microsoft adapted this versioning http://semver.org/ standard.

So, 1.0.0-previewX < 1.0.0.

Semantically this should be read as "1.0.0-previewX is preview X of version 1.0.0"

Then their own labeling does not reflect the versions indicated in the filenames.