The 1.7 branch of PrestaShop is the DEVELOPMENT version of PrestaShop.
It is constantly being improved upon. You can see it get better (and contribute to it!) here: https://github.com/PrestaShop/PrestaShop
Here are the 1.7 branch release dates:
Version number | Release date | Announcement |
---|---|---|
PrestaShop 1.7.0.0 alpha 3 | April 4th, 2016 |