As the documentation on your install of PBX in a Flash makes clear, most of the components included in the PBX in a Flash distribution are subject to the GPL2 license. You can search for the individual product licenses by issuing the command: find / -name COPYING. Because PBX in a Flash is merely an aggregation of existing works covered by GPL2 or other licenses, our production of PBX in a Flash is not itself subject to additional GPL2 restrictions. Our contribution to the community is making all of these "independent and separate works" function reliably together. We do that through a freeware installer for which source code is not available. For every product which our installer installs and which is covered by a GPL2 license, you are entitled to obtain the source code. With the exception of portions of CentOS, the remaining source code for the aggregated components in PBX in a Flash is included in the installed distribution. CentOS is an "independent and separate work" under the terms of GPL2. As such, our obligation is to provide to you the same source code that the CentOS development team makes available to us. You can download it from the authors or directly from us. If there is an object module for which the source module is not included in the CentOS repository, you can usually find it here although we have no independent obligation as an aggregator to provide it. Keep in mind that some applications are released in object module format only pursuant to a different type of license which may not include access to the source code itself. Thus, there will be no source code available. You also can download CentOS source in ISO image format from here at no cost. If you'd prefer a DVD with the source, you can purchase it directly from a CD shop such as here. If you specifically identify other missing source that is not otherwise available in the locations and links provided, we will attempt to provide it (subject to licensing restrictions) under the same terms and conditions outlined for the CentOS 5 source. See the GPL2 license or this FAQ for further details. Comments or questions about licensing should be sent to the development team through this email link. Do not post questions or requests pertaining to licensing on the forums expecting a response from the PBX in a Flash development team. Our apologies for the long-winded explanation.