Pretty slick! I like the fact that it&#x27;s open-source and client-side js. Can definitely see how this could integrate with online IDEs like Ace.<p>A few bits of feedback (although perhaps you just haven&#x27;t got around to implementing these yet):<p>- On the canvas, is there some way to make it obvious why boxes are relatively positioned a particular way? For instance, when I add a new box next to the iPhone picture, it&#x27;s not visually obvious why there is fairly sizable top padding. Maybe light grey shading to represent padding and such?<p>- Is there any reason why you wouldn&#x27;t merge the &#x27;select&#x27; tool and the &#x27;move elements&#x27; tool into the single button (and make it the default selection)?<p>- Any possibility of multi or group select, for quick deletion of multiple elements?<p>- A &#x27;new blank canvass&#x27; button might be handy.<p>Anyhow, this is some great work. I often just want to put together a very basic web interface for some personal project, and I think your tool is at exactly the right level of simplicity&#x2F;complexity for that.