Deferred gratification: Engineering for high performance garbage collection from the get go

Implementing a new programming language system is a daunting task. A common trap is to punt on the design and engineering of exact garbage collection and instead opt for reference counting or conservative garbage collection (GC). For example, AppleScriptTM, Perl, Python, and PHP implementers chose reference counting (RC) and Ruby chose conservative GC. Although easier to get working, reference counting has terrible performance and conser-vative GC is inflexible and performs poorly when allocation rates are high. However, high performance GC is central to performance for managed languages and only becoming more critical due to relatively lower memory bandwidth and higher memory latency of modern architectures. Unfortunately, retrofitting support for high performance collectors later is a formidable software engineering task due to their exact nature. Whether they realize it or not, imple