PayPal announced today that an SDK with Windows support for PayPal Here, which is a point-of-sale credit card service akin to Square, will be launching publicly later this month.
The news was originally detailed by TechCrunch, which says:
Meanwhile, the PayPal Here SDK announced previously as a pilot for iOS and Android devices will launch publicly this month including support for Windows (now in pilot testing), allowing developers to integrate Here's payment functionality into their own custom apps. That means developers will be able to build apps that offer PayPal Here checkout that works alongside other business-focused features, like CRM or inventory management systems, invoicing, and more.
Update: And just like that, PayPal has an official announcement ready:
With help from Microsoft, select small businesses can now accept credit card, debit card, and PayPal transactions using the Windows platform—via the PayPal Here SDK and, very soon, the PayPal Here app. PayPal Here compatibility will become available for the Surface Pro 3 tablet, the Lumia 830 and 635 smartphones, and other devices that operate on Windows 8.1. In addition, Microsoft and PayPal will be working with ISV partners such as Canvas and iConnectPOS, who are committed to developing custom business apps for the Windows SDK platform. For example, iConnectPOS, will be integrating the SDK so that merchants like Bridal Boutique can process sales on their Surface Pro 3 devices.
Update 2: Added promotional video to top of post.