Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.
CS183B - Startup Class - Stanford class taught by Sam Altman & guest speakers
Wirize - Payment checkout for freelancers
YC Startup Class - A live, one-hour class by Sam Altman on Platzi
Giftbit Payment API - Stripe for gift cards
Google Classroom - Learning management tool by Google