VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Crowdin - Localize your product in a seamless way
foobar2000 - An advanced freeware audio player for the Windows platform.
POEditor - The translation and localization management platform that's easy to use *and* affordable!
Winamp - Winamp is a media player that allows users to play multiple-file formats, arrange media in a varied file-management system, and play unique media with AAC encoding.
Lokalise - Localization tool for software developers. Web-based collaborative multi-platform editor, API/CLI, numerous plugins, iOS and Android SDK.