QEMU was written by Fabrice Bellard and is free software and is mainly licensed under GNU General Public License (GPL). Various parts are released under BSD license, GNU Lesser General Public License (LGPL) or other GPL-compatible licenses.[2] There is an option to use the proprietary FMOD library when running on Microsoft Windows, which, if used, disqualifies the use of a single open source software license. However, the default is to use DirectSound.