title: How different programming languages use closures?
body: <p>To my knowledge, combined with the knowledge of others, among the mainstream languages</p>
  
  <ul>
  <li>Objective C</li>
  <li>C#</li>
  <li>VB.net</li>
  <li><s>Java</s></li>
  <li>Python</li>
  <li>Ruby</li>
  <li>Javascript</li>
  <li>Lisp</li>
  <li>Perl</li>
  </ul>
  
  <p>have closures and anonymous functions. Plain C/C++ doesn't have either of those.</p>
  
  <p>Do closures in these languages have the same semantics? How important are they for everyday programming?</p>
  
  <p><strong>Some background:</strong> I've been reading about the new additions to <s>Objective</s> C that target Apple's Grand Central Dispatch and thought I should learn whether there is really <em>only one</em> or <em>different</em> ways to introduce block-like structures into the language.</p>