Feature Models (FMs) are the de-facto standard for documenting, model checking, and reasoning about the configurations of a software system. This paper introduces WebFML a comprehensive environment for synthesizing FMs from various kinds of artefacts (e.g. propositional formula, dependency graph, FMs or product comparison matrices). A key feature of WebFML is an interactive support (through ranking lists, clusters, and logical heuristics) for choosing a sound and meaningful hierarchy. WebFML opens avenues for numerous practical applications (e.g., merging multiple product lines, slicing a configuration process, reverse engineering configurable systems).