Every designer follows some line of reasoning, and makes several decisions when designing an artifact, which is the final result of this decision process. This design reasoning and decision structure, commonly called Design Rationale, is rarely captured and recorded. The reasons for this seem to be due to the lack of appropriate tools, which should capture the Design Rationale in an unobtrusive way, allowing the designer to focus on the design itself. Such tools should also allow reusing previous design solutions, helping the designer/developer to improve the quality of the solution. The goal of this dissertation is to provide means to capture, record and use Design rationale within a prototyping environment for hypermedia applications. As result, we present the HyperDE+DR environment, which combines the HyperDE environment with the Kuaba approach for recording Design Rationale. The HyperDE+DR environment automatically generates and records design decisions made by the designer during the development process. Questions and ideas are automatically generated and tentatively answered, to be reviewed later by the designer by following the OOHDM and SHDM design methods that underlie the original HyperDE environment. In addition, HyperDE+DR supports Design Rationale use, by allowing integration of previous design rationales into a design being developed. This allows improving the completeness and consistency of the resulting design, also lowering development costs.