Cloud Governance, Management, Security, and Cost Optimization.Stacklet is a commercial cloud governance platform that helps Global 2000 companies manage their security, operations, visibility, and cost optimization policies in the cloud. Stacklet is built with an open core model around the popular open source project Cloud Custodian. The Stacklet founders are the creative team behind Cloud Custodian. Stacklet provides best practice operations of Cloud Custodian, access to pre-built policies and, in the future, a fully hosted version of Cloud Custodian. With Stacklet, the founders are also working to "shift-left" the open source core. This introduces preventative control by giving developers the ability to evaluate both application and infrastructure code against their organization's governance standards early in the lifecycle.Cloud Custodian is an open-source cloud security and governance project that came out of Capital One's journey to the public cloud. Cloud Custodian is used by thousands of organizations today including power users like Intuit, Freddie Mac, FICO, Transamerica, Cox Automotive, Microsoft, Reuters, Amazon, Procter & Gamble, etc. Cloud Custodian's community is vibrant, active and rapidly growing. It includes 280+ developers, 1300+ chat participants and has over 330K downloads per month. Cloud Custodian has a critical advantage over competing solutions in that it is Policy as Code which empowers remediation and automation. Cloud Custodian's Policy as Code language is easy for IT and security admins to use because it is high order, YAML-based, and leverages a domain-specific language (DSL) where the domain is public cloud resource information. Cloud Custodian's open source core is also written in Python, so it is easily accessible for developers to use and contribute to.