The host's detected runtime name, re-exported from std-env (WinterCG Runtime Keys: 'node' | 'deno' | 'bun' | 'workerd' | 'edge-light' | …, or '' when unknown). Detected once at module load.
std-env
'node' | 'deno' | 'bun' | 'workerd' | 'edge-light' | …
''