The installation consists of code, catalog, and stellar atmosphere data. Please see more detail at http://www.eso.org/chummel/oyster/download.html and contact the author to obtain a copy of the code. The external C and FORTRAN library compiled for Linux 64-bit systems is included, but can be recompiled if necessary from the C code which can also be obtained from the author.
The file oyster.tar.gz is unpacked first, this will create the folder named oyster. Inside it, unpack catalogs.tar.gz and atmospheres.tar.gz. Two new directories are created, atmospheres and catalogs.