This is insanely cool. No matter how useful/easy your web GUI is, if you have the skill set it's always easier to just do it by hand. Huge congrats to Squarespace, I've already linked this to friends I know that use them and have had customization issues in the past.

This is a great opportunity for those who have tried to teach themselves web basics before to actually add stuff to their own sites and really expand their skillset.

I've been working on my own thing similar to this for HubSpot, having to edit using a clunky CMS live in production is super scary. I really would like to live in a world where most "we make X easier to do" companies release things like this to let people who know how to do it by hand do it faster.