OYSTER is the original interactive data reduction package developed for the Navy Prototype Optical Interferometer at Lowell (NPOI). It was created when three collections of scripts written first in PV-WAVE Command Language (PV-WAVE is a trademark of Visual Numerics, Inc.) and then also in the Interactive Data Language (IDL is a trademark of ITT Visual Information Solutions) were merged into one package for the purpose of providing a comprehensive data analysis package. (The PV-WAVE version of OYSTER is however no longer supported.) The three original collections, CHAMELEON which reduces a single night of NPOI data, AMOEBA which fits models to the calibrated visibility data of several nights, and STARBASE which implements a stellar data base and provides catalog access, are described in this User's Guide in separate parts. Also introduced are two new collections of scripts, COBRA, which provides functions for the interactive analysis of raw interferometry data (NPOI only), and PEARL, which images interferometry data.
As of 2008, OYSTER has evolved into a package also supporting the reduction and analysis of data from interferometers other than NPOI. This includes the GUI front-ends MyMidiGui and MyAmberGui to the MIA+EWS (http://www.strw.leidenuniv.nl/nevec/MIDI/index.html) and amdlib (http://www.jmmc.fr/data_processing_amber.htm) data reduction softwares for MIDI and AMBER at VLTI, respectively. Also, observation planning and advanced data analysis is available in OYSTER. Stand-alone reduction of data from other interferometers is not planned to be included in OYSTER since this involves obviously very instrument specific tasks.
Data of other interferometers can be read by OYSTER if they are stored using the OIFITS format (http://www.mrao.cam.ac.uk/research/OAS/oi_data/oifits.html).