Faustine: a vector faust interpreter test bed for multimedia signal processing. System description. Faustine is the first interpreter for the digital audio signal processing language Faust and its vector extension. This domain-specific language for sample-based audio is highly expressive and can be efficiently compiled. Faustine has been designed and implemented, in OCaml, to validate the Faust multirate vector extension proposed in the literature, without having to modify the sophisticated Faust scalar compiler. Moving to frame-based algorithms such as FFT is of paramount importance in the audio field and, more broadly, in the multimedia signal processing domain. Via the actual implementation of multidimensional FFT and morphological image processing operations, Faustine, although unable to process data in real time, illustrates the possible advantages and shortcomings of this vector extension as a language design proposal. More generally, our paper provides a new use case for the vision of interpreters as lightweight software platforms within which language design and implementation issues can be easily assessed without incurring the high costs of modifying large compiler platforms.