This states, "Every program attempts to expand until it can read mail." The law implies that all programs are now developed to evolve into toolkits and applications which are flexible and versatile. The programs that are able to satisfy the diverse needs of the customers are the ones that survive in the market as customers like to multitask.
Diagrams
Originated from/Coined by
Jamie Zawinski
Further Reading/ References
https://en.wikipedia.org/wiki/Jamie_Zawinski#Principles
http://www.catb.org/jargon/html/Z/Zawinskis-Law.html
https://medium.com/@tk512/zawinskis-law-a-modern-take-8da3cf89152b
https://softwareengineering.stackexchange.com/questions/150254/what-does-jamie-zawinskis-law-mean