Thread:Extension talk:OpenID/What version should I download?

The instructions are not at all clear. It seems my options are:
 * Download a tag. But I think, the OpenID extension doesn't have any tags
 * The latest version of one of the extensions branches. But the comments say these might be unstable.  That gives me the heebie-jeebies -- I really want a stable version.
 * A snapshot made during the release of a MediaWiki version. This also says it might be unstable.
 * clone from git. But the master branch of the git repo seems to be under (very) active development, so I'm assuming it, too, will be unstable.

I have MediaWiki 1.19 installed on my server. That's not listed in the compatibility table.

What should I do? Thanks for any advice!