BizTalk is Microsoft's platform for enterprise application integration (EAI), business process management (BPM), and business-to-business (B2B) integration. It provides a development and runtime environment for integrating systems, applications, and services through its core components like ports, schemas, pipelines, orchestrations and adapters. BizTalk handles long-running business processes within and between businesses through its publish-subscribe architecture and supports transactions that can run for weeks or months.