p3d is a general data-reduction tool for use with fiber-fed integral-field spectrographs (IFSs). The tool is built about the proprietary software IDL (EXELIS; see http://www.exelisvis.com), but does not require any license when it is used as it is.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.