Developing a comprehensive modeling tool requires big e ort and there can for sure be many technical challenges in its implementation. However, as the tool matures and gets more widely adopted by users, a set of new challenges arise. These are not so much related to the actual tool implementation, but more to questions around enabling the users to successfully use the tool.

In this talk I will share my experiences from development of modeling tools during the last 20 years. How has the focus of the industry shifted during these years, from the technical problems a tool should solve to an increased focus on \softer" issues such as usability, documentation and general user enablement? How has the introduction of new agile development methodologies helped tool vendors create better modeling tools? And what techniques can be used to learn more about the tool users and their needs? These are some examples of questions that are very relevant for anyone that wants to develop a modeling tool that someone wants to use.