Abstract: Reliability is a key concern in the current state of software industry. Producing software without defects is still very difficult. Therefore it is crucial to benefit from high-level language mechanisms such as assertions. Nevertheless contracts are mostly a specificity of the Eiffel language. This observation convinced ISE to build a new product, the Contract Wizard, which aims at providing .NET developers with the ability to add contracts to a .NET assembly independently from the .NET language it was initially written in. This paper first gives an overview of the existing implementation of Design by Contract in various programming languages. It then explains how the new ISE Contract Wizard works by providing a guided tour of the product.