Link: <a href="http://example.com/">http://example.com/</a>.

With an ampersand: <a href="http://example.com/?foo=1&bar=2">http://example.com/?foo=1&bar=2</a>

Blockquoted: <a href="http://example.com/">http://example.com/</a>

Auto-links should not occur here: <http://example.com/>

or here: <http://example.com/>