1All PulseAudio source files, except as noted below, are licensed under the GNU 2Lesser General Public License. (see file LGPL for details) 3 4However, the server side has optional GPL dependencies. These include the 5libsamplerate and gdbm (core libraries), LIRC (lirc module) and FFTW (equalizer 6module), although others may also be included in the future. If PulseAudio is 7compiled with these optional components, this effectively downgrades the 8license of the server part to GPL (see the file GPL for details), exercising 9section 3 of the LGPL. In such circumstances, you should treat the client 10library (libpulse) of PulseAudio as being LGPL licensed and the server part 11(libpulsecore) as being GPL licensed. Since the PulseAudio daemon, tests, 12various utilities/helpers and the modules link to libpulsecore and/or the afore 13mentioned optional GPL dependencies they are of course also GPL licensed also 14in this scenario. 15 16In addition to this, if D-Bus support is enabled, the PulseAudio client library 17(libpulse) MAY need to be licensed under the GPL, depending on the license 18adopted for libdbus. libdbus is licensed under either of the Academic Free 19License 2.1 or GPL 2.0 or above. Which of these applies is your choice, and the 20result affects the licensing of libpulse and thus, potentially, all programs 21that link to libpulse. 22 23Andre Adrian's echo cancellation implementation is licensed under a less 24restrictive license - see src/modules/echo-cancel/adrian-license.txt for 25details. 26 27Some other files pulled into PA source (i.e. reference implementations that are 28considered too small and stable to be considered as an external library) use the 29more permissive MIT license. These include the device reservation DBus protocol 30and realtime kit implementations. 31 32A more permissive BSD-style license is used for LFE filters, see 33src/pulsecore/filter/LICENSE.WEBKIT for details. 34 35Additionally, a more permissive Sun license is used for code that performs 36u-law, A-law and linear PCM conversions. 37 38While we attempt to provide a summary here, it is the ultimate responsibility of 39the packager to ensure the components they use in their build of PulseAudio 40meets their license requirements. 41