Safari 7.0 cannot load localhost
I believe this is a problem with WEBrick v1.3.  WEBrick isn't returning the correct content length &amp; notifies users of this:


  WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true


Trying to wget the same resource will also flag an error in the network connection as per: https://github.com/imathis/octopress/issues/1395

Chrome &amp; Firefox just display whatever content was received &amp; don't worry about the mismatch in content length.  Safari, starting with Safari 7.0 on Mavericks' 10.9 is stricter about the response &amp; treats the mismatch as a "Failure to load resource" error.  (If I had to guess they're probably trying to improve the speed so don't retry the resource and so don't get the file fully retrieved response that wget does).

If you replace WEBrick with thin, this problem should go away.  To do this on a Rack-based application try:

echo gem \"thin\" &gt;&gt; Gemfile
bundle install
rbenv rehash # if you're using rbenv
bundle exec rackup -s thin