<li>Parsing is built right into the browser.
<li>Reconnects are handled automatically by the browser.
They're support ed <a href="http://caniuse.com/#feat=eventsource"> everywhere</a> but IE, for which there are polyfills.
+ <li> support <a href="http://caniuse.com/#feat=eventsource">.
<li>They're served over plain old http, so there's no need to open a
separate port and/or run a separate server. (At the time of writing
Heroku apps can't use Websockets, for example, but they can use SSEs