to the release announcement by Andy Wingo, real-world programs often showed a speedup of 30% or more with Guile 2.2 when compared to the previous 2.0 series. Guile 2.2.0 also lowered memory usage, sped up the "eval" interpreter, provided better support for multi-core programming, and removed any fixed limit on recursive function calls. It also supported the creation of user-space concurrency facilities that multiplex millions of concurrent lightweight "fibers" and provided a complete Emacs-compatible Elisp implementation, implementing all of Elisp's features and quirks in the same way as Emacs. On 16 January 2020, Guile 3.0.0 was released with just-in-time (JIT) native code generation for much greater performance. Compared to 2.2, microbenchmark performance is around twice as good on the whole, while some individual benchmarks are up to 32 times as fast. It also featured support for interleaved definitions and expressions in lexical contexts, native support for structured exceptions, better support for the R6RS and R7RS Scheme standards and many optimizations. Emacs integration There have been several past unfinished attempts to replace or supplement Emacs's Emacs Lisp (Elisp) extension language with Guile, parallel to the efforts of supporting other languages in Guile. With version 2.0 of Guile, a new attempt at implementing Elisp on the Guile compiler tower and replacing Emacs's Elisp implementation with that of libguile has begun and made significant progress through Google Summer of Code projects. A Guile-based Emacs could offer better execution performance for Emacs Lisp, support new Emacs Lisp language features more easily, make Guile libraries written in other programming languages available to Emacs Lisp code, and allow writing Emacs extensions in other programming languages supported by Guile, all while remaining fully backward compatible with existing Emacs Lisp code bases. , the implementation had reached a stage where Guile Emacs is able to reliably run most Emacs Lisp code. Remaining problems or possible problems involve the different internal representation of Emacs Lisp strings from Scheme strings, the difference between how Emacs Lisp and Scheme treat the Boolean false and empty list objects, Emacs Lisp macros not integrating with Scheme, Emacs Lisp not having been designed for concurrency, and the portability of Guile to platforms supported by Emacs. Other concerns raised by the Emacs community include the relative sizes of the Emacs and Guile communities, and whether it would cause splitting in the community if Emacs were extensible in programming languages other than Emacs Lisp. GNU Make