Module.xs  xs source file
Module.c   generated from Module.xs
Module.o   generated from Module.c (?)
Module.so  generated from Module.o (?)
Module.bs  some 0 sized file
Module.h   C header file for Module (can also have other name)

typemap    conversion code from C datastructures to Perl and back
ppport.h   backward portability routines for the C API
           (generated by Devel::PPPort)