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.
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.
SpectMorph allows you to analyze samples of musical instruments and to combine them (morphing). It can be used to construct hybrid sounds, e.g. a sound between a trumpet and a flute, or smooth transitions, e.g. a sound that starts as a trumpet and then gradually changes to a flute. Interpolating between two samples of the same instrument (different attack velocity of a piano) could be interesting. The analysis process decomposes samples into a sum of sine waves (corresponding to the partials present in the signal, or the part of the signal perceived as "tone") and additional noise. SpectMorph is thus based on the research on Spectral Modelling Synthesis.
gst123 is a GStreamer-based command line audio player in the style of mpg123 and ogg123. The advantage over these tools is that gst123 can play every file GStreamer can, so mixed music collections with FLAC, Ogg, and MP3 files are no problem. Newer versions of gst123 additionally provide support for playing video files, while the ability to use gst123 without X11 display has been preserved.
Clementine is a modern music player and library organizer. It is inspired by Amarok 1.4, focusing on a fast and easy-to-use interface for searching and playing your music. You can search and play your local music library, and listen to Internet radio from Last.fm, SomaFM, and Magnatune. It has tabbed playlists, the ability to import and export M3U, XSPF, PLS, and ASX, visualizations from projectM, the ability to transcode music into MP3, Ogg Vorbis, Ogg Speex, FLAC, or AAC, the ability to edit tags on MP3 and Ogg files, organize your music, and download missing album cover art from Last.fm. It has native desktop notifications on Linux (libnotify) and Mac OS X (Growl), as well as remote control using a Wii Remote, MPRIS, or the command line. It can copy music to your iPod, iPhone, MTP, or mass-storage USB player. It has a queue manager.
Rubber Band is a high quality software library for audio time-stretching and pitch-shifting. It permits you to change the tempo and pitch of an audio stream or recording dynamically and independently of one another. Rubber Band is a library intended for use by developers creating their own application programs rather than directly by end users, although it does also include a simple command-line utility program that you can use for fixed adjustments to the speed and pitch of existing audio files.