markdown list of codeblock languages code example

Example 1: markdown block code

```javascript
var s = "JavaScript syntax highlighting";
alert(s);
```

```
No language indicated, so no syntax highlighting. 
But let's throw in a <b>tag</b>.
```

Example 2: markdown code block

```ruby
require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html
```