The libogg library manipulates the ogg multimedia container format, which encapsulates raw compressed data and allows the interleaving of audio and video data. In addition to encapsulation and interleaving of multiple data streams, ogg provides packet framing, error detection, and periodic timestamps for seeking.

The libtheora library implements the ogg theora video format, a fully open, non-proprietary, patent-and-royalty-free, general-purpose compressed video format.

Libao is a cross-platform audio library that allows programs to output audio using a simple API on a wide variety of platforms. It currently supports:

1. Null output (handy for testing without a sound device),

2. WAV files,

3. AU files,

4. RAW files,

5. OSS (Open Sound System, used on Linux and FreeBSD),

6. ALSA (Advanced Linux Sound Architecture),

7. aRts (Analog RealTime Synth, used by KDE),

8. PulseAudio (next generation GNOME sound server),

9. esd (EsounD or Enlightened Sound Daemon),

10. Mac OS X,

11. Windows (98 and later),

12. AIX,

13. Sun/NetBSD/OpenBSD,

14. IRIX,

15. NAS (Network Audio Server),

16. RoarAudio (Modern, multi-OS, networked Sound System),

17. OpenBSD's sndio.

FLAC stands for Free Lossless Audio Codec, an audio format that is lossless, meaning that audio is compressed in FLAC without any loss in quality.

The opusfile library provides seeking, decode, and playback of Opus streams in the Ogg container (.opus files) including over http(s) on posix and windows systems.

Icecast is a streaming media server which currently supports Ogg (Vorbis and Theora), Opus, WebM and MP3 audio streams. It can be used to create an Internet radio station or a privately running jukebox and many things in between.

Kate is an overlay codec, originally designed for karaoke and text, that can be multiplixed in Ogg. Text and images can be carried by a Kate stream, and animated. Most of the time, this would be multiplexed with audio/video to carry subtitles, song lyrics (with or without karaoke data), etc., but doesn't have to be.

Series of curves (splines, segments, etc.) may be attached to various properties (text position, font size, etc.) to create animated overlays. This allows scrolling or fading text to be defined. This can even be used to draw arbitrary shapes, so hand drawing can also be represented by a Kate stream.

Opus is a royalty-free, highly versatile audio codec. Opus-tools provide command line utilities for creating, inspecting and decoding .opus files.

Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but is also intended for storage and streaming applications. It is standardized by the Internet Engineering Task Force (IETF) as RFC 6716 which incorporated technology from Skype's SILK codec and Xiph.Org's CELT codec.

SpeexDSP is a DSP (Digital Signal Processing) library based on work from the speex codec.

RNNoise is a noise suppression library based on a recurrent neural network. The algorithm is described in Jean-Marc Valin's paper A Hybrid DSP/Deep Learning Approach to Real-Time Full-Band Speech Enhancement.

Libshout is a library for communicating with and sending data to an icecast server. It handles the socket connection, the timing of the data, and prevents bad data from getting to the icecast server.

Ogg vorbis is a non-proprietary, patent-and-royalty-free, general-purpose compressed audio format.

The package vorbis-tools contains ogg123, an ogg vorbis command line audio player; oggenc, the ogg vorbis encoder; oggdec, a simple, portable command line decoder (to wav and raw); ogginfo, to obtain information (tags, bitrate, length, etc.) about an ogg vorbis file.

The libopusenc libraries provide a high-level API for encoding Opus files and streams.

The libvorbis library implements the ogg vorbis audio format, a fully open, non-proprietary, patent-and-royalty-free, general-purpose compressed audio format for mid to high quality (8kHz-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bitrates from 16 to 128 kbps/channel.

GNU Speex is a patent-free audio compression codec specially designed for speech. It is well-adapted to internet applications, such as VoIP. It features compression of different bands in the same bitstream, intensity stereo encoding, and voice activity detection.

This module provides an XPath engine, that can be re-used by other modules/classes that implement trees.

In order to use the XPath engine, nodes in the user module need to mimic DOM nodes. The degree of similitude between the user tree and a DOM dictates how much of the XPath features can be used. A module implementing all of the DOM should be able to use this module very easily (you might need to add the cmp method on nodes in order to get ordered result sets).

The XML::Compile module suite has extensive regression testing. This module provide functions which simplify writing tests for XML::Compile related distributions.

The conventional models for parsing XML are either DOM (a data structure representing the entire document tree is created) or SAX (callbacks are issued for each element in the XML).

XML grammar is recursive - so it's nice to be able to write recursive parsers for it. XML::Descent allows such parsers to be created.

Mini-XML is a small C library to read and write XML files and strings in UTF-8 and UTF-16 encoding.

This Perl module is an interface to the GNOME project's libxslt library.

This package provides the same API as XML::Simple but is based on XML::LibXML.

XML::Compile can be used to translate a Perl data-structure into XML or XML into a Perl data-structure, both directions under rigid control by a schema.

This module extends the XML::Parser module by Clark Cooper. The XML::Parser module is built on top of XML::Parser::Expat, which is a lower level interface to James Clark's expat library. XML::DOM::Parser is derived from XML::Parser. It parses XML strings or files and builds a data structure that conforms to the API of the Document Object Model.