The current version is 3.6 (released on 6 May 2018). It delimits 386,735 administrative areas.
You can download the spatial data by country.
Downloading by country is the recommended approach. You can also download the data for the entire world.
New releases are now planned for approximately every three to six months. Version 3.4 was released in April, but had a mistake in some of the IDs and version 3.6 replaced it. The next version will be released in June 2018.
Read about the changes in our change log and learn more about these data on our meta-data page.