Throughout the past years, the engine has undergone a series of substantial revisions. While the approach, i.e., the actual implementation in sourcecode and structure, has been revamped and generally improved over and over again, the general goals have been established for years now.
The primary goal is to create an engine that enables the team to replicate all functions of Lucas Arts' SCUMM engine as well as adding optional features such as translucency (altough this has been implemented in one way or another in FoA) and hi-res filters (VGA to SVGA upscaling like in the Mac version of FoA) that can be switched off if you want it to look exactly like the original FoA. Another goal was to keep the engine as portable as possible. All system specific calls are executed through an abstraction interface, enabling easy integration with most hardware and operating systems.
The Amberfish Arts team embraces the idea of open source development. While we do not want to make the actual game content available (for the obvious reason that it would spoil the experience), there are no such concerns with the engine.
Right now there are two projects available on SourceForge (1, 2). While those are dated and do not reflect the curent state of the engine, they might be of intereste for some crazy programmers.
More information on the current implementation will follow in the near future.