Defiant is a Node.js web app framework intended to facilitate the building of disruptive technology. Let's use email as an example. If you want your own email address (e.g., @yourname.com), you have one of two options: Either set up your own email server or have someone (like Google, Zoho, etc.) host it for you, probably for a monthly/annual fee. Self-managing is extremely complicated (setting up firewalls, IMAP/POP3/SMTP access, a web-based front-end, DNS records with correct DKIM and SPF records, SSL certificates, spam filtering, antivirus, user management etc.), and if you get it wrong, the results can catastrophic. Paying someone else to manage it, however, can get expensive when you need multiple user accounts, allows for little customization, and you are always at the mercy of that 3rd party (and however they may decide to spy on you).