fretscpp is strongly inspired by the original FoF, reusing artwork to a large extent, with the source code rewritten from scratch. C++ instead of python should improve performance and allow easier support for features like whammy. It is playable, but some non-critical features are still missing.
din is a software musical instrument and audio synthesizer. Bezier curves are used to draw and sculpt waveforms, create gating and modulation (FM and AM) patterns, and create delay feedback and volume patterns. You can also create an unlimited number of drones and sculpt their waveforms. It uses JACK to output audio, and supports MIDI, OSC and IRC bot for input. din can be extended and customized with Tcl scripts.