2Checkout

PHP Payment es una librería PHP para realizar pagos en tres de las plataformas de pagos Paypal, Authorize.net y 2Checkout haciendo el proceso de pago bastante sencillo, como por ejemplo para Paypal:

// Include the paypal library
include_once ('Paypal.php');
// Create an instance of the paypal library
$myPaypal = new Paypal();
// Specify your paypal email
$myPaypal->addField('business', 'YOUR_PAYPAL_EMAIL');
// Specify the currency
$myPaypal->addField('currency_code', 'USD');
// Specify the url where paypal will send the user on success/failure
$myPaypal->addField('return', 'http://YOUR_HOST/payment/paypal_success.php');
$myPaypal->addField('cancel_return', 'http://YOUR_HOST/payment/paypal_failure.php');
// Specify the url where paypal will send the IPN
$myPaypal->addField('notify_url', 'http://YOUR_HOST/payment/paypal_ipn.php');
// Specify the product information
$myPaypal->addField('item_name', 'T-Shirt');
$myPaypal->addField('amount', '9.99');
$myPaypal->addField('item_number', '001');
// Specify any custom value
$myPaypal->addField('custom', 'muri-khao');
// Enable test mode if needed
$myPaypal->enableTestMode();
// Let's start the train!
$myPaypal->submitPayment();

PHP Payment Library for Paypal, Authorize.net and 2Checkout (2CO)