Business Logic } } closed source trade secret speci fi c to your product/business open source shared infrastructure community adding features edge case bugs found and fi xed credit cards images http webserver tcp/ip network stack memory management
let’s create inspiration • 30,000 lines • Fortran 77 • “ fi xed mode” from 1950s punchcards • fi rst 6 columns have special meanings • 2.3MB of source code in one fi le