show_in_browser is a very simple gem that opens an html string inside your default html application (you will need to set a browser to be the default application that opens up .html files.
gem install show_in_browserShowInBrowser.show("<h1>HelloWorld!</h1>")I have found this is useful for printing error messages when debugging an api that returns an HTML error page or debugging apps that are crawling websites (so I can see what they have actually crawled in the browser).
It very simply achieves this by writing the html string to /tmp/browser.html and calls open /tmp/browser.html (in bash) on it which opens it in your default html application.