runtimeagnostic

Runtime-agnostic is a quality of software components designed to execute across multiple runtime environments without relying on runtime-specific features or behaviors. A runtime here refers to the execution environment, such as a virtual machine, interpreter, or platform runtime (for example, the Java Virtual Machine, .NET CLR, Node.js, or a WebAssembly engine).

A runtime-agnostic component aims to provide a stable interface and behavior across runtimes, typically by targeting portable languages or intermediate representations, by abstracting runtime services through explicit interfaces, and by avoiding APIs that are unique to a single runtime.

Benefits include greater portability, reuse across ecosystems, easier testing in multiple environments, and reduced vendor lock-in. It can simplify deployment in heterogeneous environments and enable polyglot ecosystems.

Tradeoffs include potential performance gaps, larger codebases to support multiple runtimes, limited access to runtime-specific optimizations, and more complex debugging and profiling due to cross-runtime variability.

Examples include WebAssembly modules that run in browsers and standalone runtimes; Kotlin Multiplatform projects that compile to JVM, JavaScript, or native; portable libraries such as protocol buffers and JSON libraries designed to work across runtimes; and software designed to run on multiple runtimes via runtime adapters.