Like Google Mail, Google Docs almost entirely consists of obfuscated JavaScript, some of it common between the two. Its HTML structure is quite simple, though it uses hidden iframes for various purposes (one for key input and another for calculating word widths, amongst others). Over the course of the couple of months I identified over 30 distinct issues that needed fixing, and I’ll discuss the more interesting ones in the second section of this blog.

As with Gmail, I believe Flow is the only browser engine written after Google Docs that can run Google Docs.

source: HN