Register-based virtual machines
Parrot virtual machine
Parrot was a register-based process virtual machine designed to run dynamic languages efficiently. It is possible to compile Parrot assembly language and Parrot intermediate representation (PIR, an intermediate language) to Parrot bytecode and execute it. Parrot is free and open source software. Parrot was started by the Perl community and is developed with help from the open source and free software communities. As a result, it is focused on license compatibility with Perl (Artistic License 2.0), platform compatibility across a broad array of systems, processor architecture compatibility across most modern processors, speed of execution, small size (around 700k depending on platform), and the flexibility to handle the varying demands made by Raku and other modern dynamic languages. Version 1.0, with a stable application programming interface (API) for development, was released on March 17, 2009. The last version is release 8.1.0 "Andean Parakeet". Parrot was officially discontinued in August 2021, after being supplanted by MoarVM in its main use (Raku) and never becoming a mainstream VM for any of its other supported languages. (Wikipedia).
