Parrot

Parrot is a virtual machine for Perl 6 and other dynamic languages that started its developement together with Perl 6 late in the year 2000. It was originally designed and developed by Dan Sugalski, later also Leo(pold) Tötsch and others, but todays core team include Allison Randal, chromatic, Will Coleda, Jerry Gay, Stephen Weeks, Vasily Chekalkin and also Patrick_Michaud, Jonathan_Worthington.

Parrot has its own Organisation with its own Website and a news aggregator where you can read what the core team is currently doing.

Parrot has a register based design that is very different from other VM like JavaVM or the .Net-VM which are stackbased. That has 2 major advantages. Because most CPU are also register based, some type of register and their oprations can be mapped on native CPU oprations which will make that VM faster. The switch between threads or even simple jumps inside a program is also faster, because in Parrot we can move from one set of registers to an other in one operation and don't need push one set of values that need to be saved on one stack and pull from the other all the values we need to run the program on the other position. In Parrot are also Register that are objects and behave e.g. like Perl strings.

Because Parrot is a software CPU it has its own Assembler language called PASM. But writing sofware in PASM is very slow, thatswhy there is also PIR. Honestly that is still low level, slow to write and not the way most programmer are used to write programms. So the Parrot design team created the Parrot Compiler Tools (PCT) that help language developers to write compiler like Rakudo for Parrot, including Not Quite Perl (NQP) a subset of Perl 6 that makes it very easy and convenient for Perl-people to write programs for Parrot.