There's a new posting on PHPEverywhere this morning pertaining to Parrot - what it is, and how it can be good for PHP.

An interesting presentation on Parrot's Internal Implementation (pdf) by Dan Sugalski. Don't be fooled by the sub-title: Implementing an Interpreter. Parrot can be run in Just-In-Time compiler mode - basically compiled into fast machine language, just like C or C++.

That's why the prospect of PHP6 running on Parrot is so attractive. A x10 improvement in performance for CPU intensive algorithms (such as MD5 or crc32) would not be surprising.

The last link there references an interview with Rasmus from previously in the year (part of which discusses Parrot replacing Zend...)