Wolfram Alpha‘s computational knowledge engine or answer engine developed by Wolfram Research, which can be consumed as a service as well. Users submit queries and computation requests. Wolfram Alpha then computes answers and relevant visualizations from a knowledge base of curated, structured data that come from other sites and books. 2000 non-commercial API calls per month are free.

They provide a nice set of API Language Libraries to get you started.

<?php  
  $appID = 'PLACE_YOUR_APP_ID_HERE';

  if (!$queryIsSet) die();

  $qArgs = array();
  if (isset($_REQUEST['assumption']))
    $qArgs['assumption'] = $_REQUEST['assumption'];

  // instantiate an engine object with your app id
  $engine = new WolframAlphaEngine( $appID );

  // we will construct a basic query to the api with the input 'pi'
  // only the bare minimum will be used
  $response = $engine->getResults( $_REQUEST['q'], $qArgs);

  // getResults will send back a WAResponse object
  // this object has a parsed version of the wolfram alpha response
  // as well as the raw xml ($response->rawXML) 
  
  // we can check if there was an error from the response object
  if ( $response->isError() ) {
?>
  <h1>There was an error in the request</h1>
  </body>
  </html>
<?php
    die();
  }
?>

<?php

$appID = 'PLACE_YOUR_APP_ID_HERE';

if (!$queryIsSet) die();

$qArgs = array();

if (isset($_REQUEST['assumption']))

$qArgs['assumption'] = $_REQUEST['assumption'];

// instantiate an engine object with your app id

$engine = new WolframAlphaEngine( $appID );

// we will construct a basic query to the api with the input 'pi'

// only the bare minimum will be used

$response = $engine->getResults( $_REQUEST['q'], $qArgs);

// getResults will send back a WAResponse object

// this object has a parsed version of the wolfram alpha response

// as well as the raw xml ($response->rawXML)

// we can check if there was an error from the response object

if ( $response->isError() ) {

<h1>There was an error in the request</h1>

</body>

</html>

<?php

die();

}

Developer Portal

Empower your website with Wolfram Alpha

Alexander