OpenCost is an open-source initiative that is vendor-neutral, designed to measure and allocate costs associated with cloud infrastructure and containers in real-time. Developed by experts in Kubernetes and backed by practitioners in the field, OpenCost brings transparency to the often opaque spending patterns associated with Kubernetes. It offers flexible and customizable options for cost allocation and monitoring of cloud resources, facilitating accurate showback, chargeback, and continuous reporting. The tool provides real-time cost allocation that can be examined down to individual containers, ensuring precise tracking of expenses. It effectively allocates costs for in-cluster resources, including CPU, GPU, memory, load balancers, and persistent volumes. Additionally, OpenCost features dynamic asset pricing by integrating with billing APIs from AWS, Azure, and GCP, while also accommodating on-premises Kubernetes clusters with tailored pricing solutions. Beyond the Kubernetes cluster, it can monitor expenses from cloud providers related to resources such as object storage and databases, as well as other managed services. Furthermore, it seamlessly integrates with other open-source tools, allowing for convenient exports of pricing data to platforms like Prometheus, enhancing its utility in cost management. This makes OpenCost a comprehensive solution for organizations seeking to maintain control over their cloud spending effectively.