BuiltWith is a quick and dirty tool that does one thing and it does it very well: It tells you what specific technologies any given website was created with: down to the Analytics/Tracking they are using, Widgets they have installed, their back-end technologies (also known as “the stack”), the technology they are using for mobile, payment processing, and JavaScript Libraries. You also see information about Advertising, email sending providers, SSL certificates, CDNs, the document encoding, and more.
It’s kind of like peaking behind the curtain.
