Coinbase - Bitcoin, safe and easy.
CoinGate - CoinGate is a payment gateway for Bitcoin, XRP, Litecoin, Ethereum and 50 other cryptocurrencies.
Circle Pay - Send money like a text. No fees. No borders. No one else is doing this.
NOWPayments - NOWPayments is a crypto payment gateway that supports more than 300 cryptocurrencies, including fiat, and offers simple tools to accept crypto payments, like a crypto payments API, plugins, invoices.
Blockonomics - Top Bitcoin payment solution since 2015. Merchant gateways for WooCommerce, WHMCS and others. #1 wallet watcher & more. Be your own bank.
Hyperledger - Hyperledger is a multi-project open source collaborative effort hosted by The Linux Foundation, created to advance cross-industry blockchain technologies.