FFmpeg - Open source multimedia suite for conversion, playback, profiling, and streaming.
HandBrake - HandBrake allows users to easily convert video files into a wide variety of different formats.
Xvid - Xvid is an open-source research project focusing on video compression and is a collaborative...
Format Factory - Format Factory is software that allows the user to convert media into various file formats. The software is a product of PC Free Time, a Chinese software development company. Read more about Format Factory.
FLAC - A free, open source codec for lossless audio compression and decompression
File Converter - Convert & compress everything in 2 clicks!