OpenTracing, OpenCensus, and OpenMetrics are projects aimed at creating standards for application performance monitoring and collecting metric data. While they overlap in terms of goals, each project takes a different approach to observability and instrumentation. OpenMetrics focuses on creating a standard format for exposing metric data, while OpenTracing and OpenCensus focus on creating a standard for distributed tracing. Both projects are vendor-neutral but rely on the backend projects and vendors to implement their own tracers and instrumentation. Distributed tracing is critical for understanding how a request moves across multiple services, packages, and infrastructure components, especially in microservices architecture. Projects like OpenTracing, OpenCensus, and OpenMetrics try to address this by providing standards for instrumentation and collecting data, enabling APM vendors and developers the ability to build portable tracers and instrumentation to track a request as it travels through each service within an application.