It is widely accepted that modeling in software engineering increases productivity and results in better code quality. Yet, modeling adoption remains low. The open source community, in particular, remains almost entirely code centric. In this paper, we explore the reasons behind such limited adoption of modeling practices among open source developers. We highlight characteristics of modeling tools that would encourage their adoption. We propose Umple as a solution where both modeling and coding elements are treated uniformly. In this approach, models can be manipulated textually and code can be edited visually. We also report on the Umple compiler itself as a case study of an open source project where contributors, using the above approach, have and continue to routinely commit code and model over a number of years.