Combine four key technologies to build great solutions for your clients and business users. Build client-side web parts using the SharePoint Framework (SPFx) along with the open-source toolchain. The PnP-JS-Core library allows you to do a lot of work against the SharePoint REST API with just a few lines of code — sometimes even a single line of code! ReactJS is a view library that allows you to build lightning-fast user interfaces using a powerful component model. Finally, the Office UI Fabric, available in several forms including React components, allows you to build great-looking solutions that follow the design guidelines for SharePoint and Office Add-ins. Four great technologies in their own right, but in combination they allow you to deliver amazing SharePoint solutions with minimal effort.