The Advanced Linux Sound Architecture is composed of several parts. The first is a fully modularized sound driver which supports module autoloading, devfs, isapnp autoconfiguration, and gives complete access to analog audio, digital audio, control, mixer, synthesizer, DSP, MIDI, and timer components of audio hardware. It also includes a fully-featured kernel-level sequencer, a full compatibility layer for OSS/Free applications, an object-oriented C library which covers and enhances the ALSA kernel driver functionality for applications (client/server, plugins, PCM sharing/multiplexing, PCM metering, etc.), an interactive configuration program for the driver, and some simple utilities for basic management.
The Snack sound extension adds commands for sound play/record and sound visualization, e.g. waveforms and spectrograms. It supports in- memory sound objects, file based audio, streaming audio, WAV, AU, AIFF, and MP3 file formats, synchronous and asynchronous playback. The visualization canvas item types update in real-time and can output postscript. New commands and file formats can be added using the Snack C-API.
The Java Media Framework (JMF) is an API for incorporating audio, video, and other time-based media into Java applications and applets. It is an optional package that extends the multimedia capabilities on the Java2 platform. The Blackdown JMF is a Performace Pack which includes native code in order to provide faster processing and tighter integration with Linux than the all-Java version.
ecasound.el is an interface to ecasound from within Emacs. It allows you to use an inferior ecasound process in an comint-derived mode. It features context-sensitive completion and wizards for adding chainoperators and the like. It allows you to write ECI-based applications in Elisp.
The Helix DNA Producer is a multi-format media-encoding engine for creating streaming broadcasts, on-demand streaming content, and downloadable audio video files. It supports RealAudio, RealVideo, and Ogg Vorbis, and includes many input and output filters, variable bitrate encoding support, option for two-pass encoding, audio gain control, and Firewire support.
JACK is a low-latency audio server. It can connect a number of different applications to an audio device, as well as allowing them to share audio between themselves. Its clients can run in their own processes (i.e., as normal applications), or can they can run within the JACK server (as a "plugin"). JACK is different from other audio server efforts in that it has been designed from the ground up to be suitable for professional audio work. This means that it focuses on two key areas: synchronous execution of all clients, and low latency operation.
Audio::Xmpcr is a Perl API to the XM PCR Satellite radio. It offers two different operating modes (direct and remote+daemon) via a single interface, continuous device polling for instant, accurate song listings, auto notification when songs change on any channel, and a few utility programs including a Web interface for remote control/listening to the radio via icecast, a stream ripper that divides songs up into properly-named wav files (for making MP3s), and a finder that searches channels for the song(s) wanted, and records just those.