anchor.diff:  
   Developed by the https://groups.google.com/forum/#!forum/killbilling-users[Kill Bill community], you can use the Simple Tax plugin for fixed-rate taxes (for example, VAT). 
   
  +[[testing]]
   === Testing
   
   Don’t worry - we’re not going to test you on your Kill Bill knowledge! Instead, we have a couple of plugins: one to test a catalog (assuming you are using a customized one) and another one to test payments. 
  
positive.code: 
  The Analytics & Reporting plugin is a _notification_ plugin type. You can read about notification plugins in https://docs.killbill.io/latest/notification_plugin.html[_Developing a Notification Plugin_].
  
  === Coupons/Entitlement
  
  https://github.com/killbill/killbill-coupon-plugin-demo[GitHub] | 
  
negative.code: To learn about _payment_ plugins, see the
  https://docs.killbill.io/latest/payment_plugin.html[_Payment Plugin Overview_].
  
  [[payment_gateways]]
  === Payment Gateways
  
  Our current open-source payment plugins are for Adyen, Braintree, Qualpay, and Stripe. For more information on payment plugins in general, see the Payment Plugin Guide. 
  