Creating serverless applications involves packaging serverless functions with direct and runtime dependencies into a chosen Function as a Service (FaaS) platform. Currently, the lack of a common standard for function packaging leads to vendor-specific lock-in, hindering function portability across different platforms. The article advocates for an open, extensible "Function Package" standard that separates function code and direct dependencies from runtime-specific configurations, allowing functions to be reused across multiple serverless environments with only the necessary external configurations added at installation. The proposal highlights the advantages of container runtimes and custom function runtimes while noting the high coupling between functions and runtime environments in existing models. By creating language-specific profiles and leveraging stable dependency references, this approach aims to enable repeatable, efficient deployments and reduce cloud-vendor dependency, allowing developers to focus more on application logic rather than operational details.