Introduction
Parrot is a language-neutral virtual machine for dynamic languages such as Ruby, Python, PHP, and Perl. It hosts a powerful suite of compiler tools tailored to dynamic languages and a next generation regular expression engine. Its architecture is fundamentally different than existing virtual machines such as the JVM or CLR, with optimizations for dynamic languages included, a register-based system rather than stack-based, and the use of continuations as the core means of flow control.
The name "Parrot" was inspired by Monty Python's Parrot sketch. As an April Fools' Day joke in 2001, Simon Cozens published "Programming Parrot", a fictional interview between Guido van Rossum and Larry Wall detailing their plans to merge Python and Perl into a new language called Parrot (http://www.perl.com/pub/a/2001/04/01/parrot.htm).
Parrot Resources
The starting point for all things related to Parrot is the main website http://www.parrot.org/. The site lists additional resources, well as recent news and information about the project and the Parrot Foundation, which holds the copyright over Parrot and helps guide development and the community.
Documentation
Parrot includes extensive documentation in the distribution. The full documentation for the latest release is available online at http://docs.parrot.org/.
Mailing Lists
The primary mailing list for Parrot is parrot-dev@lists.parrot.org. If you're interested in getting involved in development, you may also want to follow the parrot-commits and parrot-tickets lists. Information on all the Parrot mailing lists and subscription forms for each is available at http://lists.parrot.org/mailman/listinfo.
The archives for parrot-dev are also available on Google Groups at http://groups.google.com/group/parrot-dev and via NNTP at nntp://news.gmane.org/gmane.comp.compilers.parrot.devel.
IRC
Parrot developers and users congregate on IRC at #parrot on the irc://irc.parrot.org server.
It's a good place to get real-time answers to questions or see how things are progressing.
Issue Tracking & Wiki
Parrot developers track issues with a Trac site at https://trac.parrot.org/. Users can submit new tickets and track the status of existing tickets. The site also includes a wiki used in project development, a source code browser, and the project roadmap.
Parrot Development
Parrot's first release occurred in September 2001. It reached 1.0 in March 2009. The Parrot project makes releases on the third Tuesday of each month. Two releases a year — occuring every January and July — are "supported" releases intended for production use. The other ten releases are development releases for language implementers and testers.
Development proceeds in cycles around releases. Activity just before a release focuses on closing tickets, fixing bugs, reviewing documentation, and preparing for the release. Immediately after the release, larger changes occur, such as merging branches, adding large features, or removing deprecated features. This allows developers to ensure that changes have sufficient testing time before the next release. Releases also encourage feedback as casual users and testers explore the newest versions.
The Parrot Team
Parrot developers fulfill several rules according to their skills and interests.
- Architect The architect has primary responsibility for setting the overall direction of the project, facilitating team communication, and explaining and evaluating architectural issues. The architect makes design decisions and documents them in Parrot Design Documents, and oversees design and documentation work delegated to other members of the team to provide a coherent vision across the project. The architect also works with the release managers to develop and maintain the release schedule. Allison Randal currently leads the Parrot project as architect.
- Release Managers Release managers manage and produce monthly releases according to the release schedule. Parrot has multiple release managers who rotate the responsibility for each monthly release. The release managers develop and maintain the release schedule jointly with the project architect.
- Metacommitter Metacommitters manage commit access to the Parrot repository. Once a contributor is selected for commit access, a metacommitter gives the new committer access to the repository and the bugtracker. The architect is a metacommitter, but other team members also hold this role.
- Committer Contributors who submit numerous, high-quality patches may be considered to become a committer. Committers have commit access to the full Parrot repository, though they often specialize on particular parts of the project. Contributors may be considered for commit access either by being nominated by another committer, or by requesting it.
- Core Developer Core developers develop and maintain core subsystems such as the I/O subsystem, the exceptions system, or the concurrency scheduler.
- Compiler Developer Compiler developers develop and maintain one or more Parrot front-end compilers such as IMCC, PGE and TGE.
- High-Level Language Developer Developers who work on any of the high-level languages that target Parrot—such as Lua, Perl, PHP, Python, Ruby, or Tcl—are high-level language developers. The Parrot repository includes a few example languages. A full list of languages is available at https://trac.parrot.org/parrot/wiki/Languages.
- Build Manager Build managers maintain and extend configuration and build subsystems. They review smoke reports and attempt to extend platform support.
- Tester Testers develop, maintain, and extend the core test suite coverage and testing tools. Testers are also responsible for testing goals, including complete coverage of core components on targeted platforms.
- Patch Monsters Hackers and developers submit patches to Parrot every day, and it takes a keen eye and a steady hand to review and apply them all. Patch monsters check patches for conformance with coding standards and desirability of features, rework them as necessary, verify that the patches work as desired, and apply them.
- Cage Cleaners The cage cleaners ensure that development follows the project's coding standards, documentation is complete and accurate, all tests function properly, and new users have accurate and comprehensive coding examples. A special class of Trac tickets is available for these tasks. Cage cleaning tasks run the gamut from entry-level to advanced; this is a good entry point for new users to work on Parrot.
- General Contributor Contributors write code or documentation, report bugs, take part in email or online conversations, or contribute to the project in other ways. All volunteer contributions are appreciated.
Licensing
The Parrot foundation supports the Parrot development community and holds trademarks and copyrights to Parrot. The project is available under the Artistic License 2.0, allowing free use in commercial and open source/free software contexts.