This is GDS2, a module for quickly creating programs to read, write, and manipulate GDS2 (GDSII) stream files. You can get a significant (~30%) speedup by using the compiled C additions to the module (Build option). Send feedback/suggestions to Schumack@cpan.org use cpansign -v to check file integrity GDS2 should be able to handle any size gdsii file but is generally considered too slow for anything larger than a few megabytes in size. If your files are are closer to the gigabyte range you should check out the gdt programs at: http://sourceforge.net/projects/gds2/