Cookbook /
PayPalButtons  Creating neat markup for otherwise sloppy PayPal button forms (stable)
PayPalButtons2  A flexible PayPal "Buy Now" button markup (Works for contributor's account)
PayPalCart  Provides markup for PayPal shopping cart buttons. (in active use)
PPDonate  Create links to accept donations via PayPal (Beta)
SagePayPayment  Provides SagePay (previously known as Protx) payment integration into PmWiki (Beta / RC (works for me))
ShoppingCartProposal  A proposal for how to develop a shopping-cart add-on for PmWiki. (pre-alpha)
SimpleCart  integration of simple javascript shopping cart with PayPal or Google checkout (stable)