Ardour is an audio processing and editing application. It integrates broad hardware support, JACK and ALSA backends, flexible recording features, multi-channel nesting, import and exporting various file formats, comes with ready to use samples from freesound.org. It has a pretty editing UI, mixing, routing, monitoring, panning. Ardour allows non-destructive and non-linear editing, can be used for augmenting audio layers in video files even. And comes with many effect, input and output plugins. I
Qtractor is an Audio/MIDI multi-track sequencer application written in C++ with the Qt framework. Target platform is Linux, where the Jack Audio Connection Kit (JACK) for audio, and the Advanced Linux Sound Architecture (ALSA) for MIDI, are the main infrastructures to evolve as a fairly-featured Linux desktop audio workstation GUI, specially dedicated to the personal home-studio.
Calf Studio Gear is a stack of audio effect plugins for JACK sound servers and LV2 hooks. It contains instruments and tone generators, dynamic processors, digital effects, modulators, filters and equalizers, delay effects, distortion and enhancement filters, as well as some tools aimed at professionals.
Xjadeo is a software video player that displays a video-clip in sync with an external time source (MTC, LTC, JACK-transport). Xjadeo is useful in soundtrack composition, video monitoring or any task that requires to synchronizing movie frames with external events.