KNX Association - In April, you can upgrade your ETS4 or ETS5 Lite with 27% rebate by using the voucher code AP2017LTEPRO56SKW73R6X. More info on how to order can be found here:
Der Weg zur kostenfreien ETS-Lizenz | Knipp
ETS5 Professional (fast) kostenlos? KNX kostengünstig konfigurieren | smarthomebau.de
Der Weg zur kostenfreien ETS-Lizenz | Knipp
Special offer for ETS5 Lite + 1 free ETS Inside KNX Association [Official website]