software is created over different pashes programs runing under different platforms like STANDERD

IBM CLONES and prototyping computers  like ARDUINO.

firt phase is software engineering .....

requirenemets ghathering :
legacy backword compatibilty , plug and play , ENVIRONEMENT FREINDLY , HUMAN RESOURCES

implementing :
programming language , compilers , INTEGRATED DEVELOPMENT ENVIRONMENT

testing :
blackbox , whitebox testing , documentation , moneky test ( FUZZING,....)

shipping:
WORLD WIDE WEB , DISK DRIVE , DONGEL .....

marketing:
FEATURES

developement:
FIXING ERRORS , IMPLEMENTINING NEW FEATURES

and the loop repeat from implementing.