I am trying to do a POC of integrating payment gateway(using PayPal) with Salesforce. I have found multiple App Exchange products. However I would like to create a do the POC with Apex Code. I am not sure of the accounts of PayPal that can be used. Any blog/documentation/steps/reference to answers to similar questions would be really helpful.
I tried with this blog http://techsahre.blogspot.in/2011/01/simple-paypal-integration-with.html.
However, I am not being able to setup the accounts as I am not finding links that has been described in the Article.