The development and porting of virtual instruments or audio effects on the Web is a hot topic. Several initiatives are emerging, from industry-driven ones (e.g., Propellerhead Rack Extension running on the Web2), to more community based open-source projects. Most of them aim at adapting existing code bases (usually developed in native languages like C/C++) as well as facilitating the use of existing audio Digital Signal Processing (DSP) languages and platforms. Our two teams previously presented an open format for WebAudio Plugins coined WAP [2]. It aims at: (i) improving the interoperability of audio/MIDI plugins developed using pure Web APIs, (ii) porting existing native code bases, or (iii) using Domain Specific Languages (DSL). In this paper, we present a solution based around FAUST DSL, its Web-based editor, and the integration of a plugin GUI editorallowing to directly test, generate and deploy WAP plugins. We also evoke our collaborative work: one team hatching and improving FAUST, the other working on the recreation of tube guitar amplifiers and pedalboards within Web browsers. So as to fully illustrate the FAUST online framework, a case study is detailed with complete workflow, from the FAUST DSP source code written and tested in a fully functional online editor, to a self-contained plugin running in a separate host application.