On December 7 and 8, 2011, the Wo?-Congress will be held for the 2nd time, this time at the Science Park in Gelsenkirchen. The central theme this year is mobile applications and solutions based on geoinformation and navigation data. This topic is also currently a priority in terrestris’ development work, and we have taken this as an opportunity to present ourselves at the event in the form of a lecture by Marc Jansen. The lecture, scheduled for December 7, is entitled “Wo?mit Mobile? – Development of a WebMapping Client on mobile devices.”