Audacity is a free, easy-to-use audio editor and recorder for various operating systems. It can be used to record live audio, to convert tapes and records into digital recordings or CDs and to edit (Ogg Vorbis, MP3, and WAV) sound files.

VLC (initially VideoLAN Client) is a multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, ...) as well as DVDs, VCDs, and various streaming protocols. It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network.

Mixxx is an open source DJ tool designed for both professional and semi-professional users. It has a number of key features to help the DJ in the live mix and reads most popular sound formats, including MP3, Ogg Vorbis, Wave and Aiff.

MediaPortal is an open source application which allows you to listen to music & radio, watch and store your videos and DVDs, view, schedule and record live TV as a digital video recorder and more.

MuseScore is a free scorewriter for Windows, macOS, and Linux supporting a wide variety of file formats and input methods.

Openshot is a free, easy-to-use video editing software package for Linux.

Ogg Vorbis is the opensource-successor of mp3. It provides higher compression rates with better audio quality. In Linux, the ogg vorbis format is already the standard format for audio compression. Information on encoders and players (also for Windows and Mac) can be found at www.vorbis.com.

FLAC stands for Free Lossless Audio Codec and is capable of compressing audio without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio.