The “hero unit” at the top should contain a big link to install it (appropriately worded to indicate that it’s just sending you to instructions in a README on GitHub). Another big button link to the screencasts would probably help, since most people won’t understand what Xiki is without them. Alternatively, have a “features” page with a list of features and large, static screenshot demonstrating each of them.
"Type and double-click Type a word, any word. Then double click on it or type control-return (or command-return). For example type: git, bootstrap, mysql, mongo, rails, node, coffee, js, dom, jquery, svg, ruby code, file paths, url's, shell commands, etc."
I can type and double click on any word in this text box. It doesn't do anything, but I can poke at them all I want. Or, how about this:
"Wiki inspired Everything is editable text. Type commands anywhere. Edit the output. (Vs. typing commands at the bottom, and read-only output.) Intermix menus, headings, bullet points, wherever you want. Xiki == executable wiki."
Why would I want to do any of that? Edit the output of commands?