As of 4.4.2 of X, we are excited to announce validated development environments. Now with each purchase of X you’ll be able to run a validated development and production environment simultaneously. Keep in mind that the license terms are still the same. Each X license is to be used on one production domain only. More info can be found on the changelog for this release as well as the FAQ section at the bottom of your license page when logged into your Themeco account.