Despite the considerable effort invested by industry and academia in modeling standards such as UML (Unified Modeling Language), software modeling has long played a subordinate role in commercial software development. Although modeling is generally perceived as state of the art and thus as something that ought to be done, its appreciation seems to pale along with the progression from the early, more conceptual phases of a software project to those where the actual handcrafting is done. As a matter of fact, while models have been found useful for documentation purposes and as rough sketches of implementations, their ultimate value has been severely limited by their ambiguity and tendency to get out of sync with the final code. More recently, hopes that modeling might reach its deserved place in the software engineering process have been refueled by so-called MDD (model-driven development) initiatives, most prominently advanced by IBM and the OMG (Object Management Group). The underlying idea is to promote models to the primary artifacts of software development, making executable code a pure derivative. According to this development paradigm, software is generated—with the aid of suitable transformations—from a compact description (the model) that is more human readable and maintainable than any other form of software specification in use today. Using a metaphor from biology, such a model would be the construction plan—the DNA—of software, and the transformations the ribosomes of the construction process. Today, increasing numbers of success stories accompany major releases of software development products that claim to have made MDD a reality, and market pressure will soon force even conservative CTOs to look into this emerging technology. As a colleague recently predicted: “In the future, there won’t be any programming jobs in this country. Instead, we will make models and ship them offshore, where programmers will turn them into code.” “False,” another colleague responded, “we won’t ship the models, but transform them ourselves. However, we will do it all automatically.” Take your choice. In the following Dr. Con, known as a harsh critic of today’s modeling languages and a skeptic of the feasibility of MDD, and Dr. Pro, a believer in the MDD vision, discuss whether MDD is flawed from the beginning or represents the most promising new development paradigm today.