Thanks for asking!
The code in https://github.com/sharetribe/sharetribe is the same code that is running the marketplaces in the sharetribe.com hosting. When ever we merge something to sharetribe master branch, we deploy that code to sharetribe.com.
We do have a few private repositories in Github. We have one repository for our marketing site (your screenshot). Then we have one repository for our new search service (Clojure + ElasticSearch). We plan to open that repository but we don’t have a timeline for this. Then we have few repositories for our hosting setup configs, internal tooling, etc.
I wouldn’t say that there are two different Sharetribe versions. Currently the new search engine is a big piece that is not opened yet, but other than that, all the code needed for running a marketplace on Sharetribe is available for public.