Comp.lang.ruby FAQ

RUBY NEWSGROUP FAQ – Welcome to comp.lang.ruby! (Revised 2005-4-14)

This FAQ contains information for those who want to:

  1. learn more about Ruby, and want to
  2. post to comp.lang.ruby or to the ruby-lang mail list, or want to
  3. provide anonymous feedback to help us improve Ruby.

This FAQ will be posted monthly. If you are reading this material
via the mailing list or the newsgroup, note that you can find it on
the web at:

A German version of this FAQ is maintained by Josef “Jupp” Schugt. It
can be
found at:

Note that this is not the Ruby language FAQ! This can be found at:


1 About Ruby
1.1 What is Ruby?
1.2 Where can I find out more about Ruby?
2 About comp.lang.ruby.
2.1 Tell me about comp.lang.ruby.
2.2 Tell me the posting guidelines for comp.lang.ruby.
2.3 Tell me about the prolific Matz poster.
2.4 How do the mailing list and newsgroup interrelate?
2.5 What are these 6-digit message numbers?
2.6 What is "POLS"?
3 Anything else?

1 About Ruby

1.1 What is Ruby?

Ruby is a very high level, fully OO programming language. Indeed,
Ruby is one of the relatively few pure OO languages. Yet despite
its conceptual simplicity, Ruby is still a powerful and practical
"industrial strength" development language.

Ruby selectively integrates many good ideas taken from Perl,
Python, Smalltalk, Eiffel, ADA, CLU, and LISP. Ruby combines
these ideas in a natural, well-coordinated system that embodies
the principles of least effort and least surprise to a
substantially greater extent than most comparable languages --
i.e., you get more bang for your buck, and what you write is more
likely to give you what you expected to get.  Ruby is thus a
relatively easy to learn, easy to read, and easy to maintain
language; yet it is very powerful and sophisticated.

In addition to common OO features, Ruby also has threads,
singleton methods, mixins, fully integrated closures and
iterators, plus proper meta-classes.   Ruby has a true
mark-and-sweep garbage collector, which makes code more reliable
and simplifies writing extensions.  In summary, Ruby provides a
very powerful and very easy to deploy "standing on the shoulders
of giants" OO scaffolding/framework so that you can more quickly
and easily build what you want to build, to do what you want to

You will find many former (and current) Perl, Python, Java, and
C++ users on comp.lang.ruby that can help you get up to speed in

Finally, Ruby is an "open source" development programming

1.2 Where can I find out more about Ruby?

If you're into IRC, check out #ruby-lang on FreeNode. There are
also other channels -- see

There are also many web and print resources listed below:

Ruby's home web site:  (Ruby home page)

        Follow the links to documentation, downloads, the Ruby
        Application Archive, the Ruby mail list archives, and
  lots of other interesting information.

RubyForge (A major repository with hundreds of Ruby projects) (A large source of Ruby documentation)

RubyCentral.COM (Ruby's other major on-line docs and links site):

RubyCentral.ORG (Home of RubyCentral, Inc.)

RubyGarden (An important wiki site, very content-rich)

Ruby FAQ:

Ruby U.'s Guide (introductory tutorial):

_Why's Poignant Guide to Ruby (A Ruby tutorial on acid, featuring
    cartoon foxes)

Note: The list of books below is now frozen. I don't
want to maintain this forever. We all hope the number
of Ruby books increases, of course.

English language Ruby books (recent publication order):

    Programming Ruby: A Pragmatic Programmers Guide
    2nd edition. See below.

    Making Use of Ruby

by Suresh Mahadevan
Wiley; ISBN 0-471-21972-X (2002)

    Teach Yourself Ruby in 21 Days
    by Mark Slagell
    Sams; ISBN: 0672322528 (March, 2002)

    Ruby Developer's Guide
    by Michael N., Robert F., Lyle J.
    Publishers Group West; ISBN: 1928994644 (February, 2002)

    The Ruby Way
    by Hal F.
    Sams; ISBN: 0672320835 (December, 2001)

    Ruby In A Nutshell
    by Yukihiro M.
    O'Reilly & Associates; ISBN: 0596002149 (November, 2001)

    Programming Ruby: A Pragmatic Programmers Guide
    by Dave T. and Andrew H.
    Addison Wesley; ISBN: 0201710897 (2000)
    (As of Sept 2004, there is a second edition also. It is
     not open-sourced at this time.)
    Online version:

(Note that this is a legal first edition.)

German language Ruby books (author alpha order):

    Das Einsteigerseminar Ruby. Der methodische und
    ausführliche Einstieg.
    by Dirk Engel and Klaus Spreckelsen
    ISBN: 3826672429

    Programmieren mit Ruby
    by Armin R., Stefan S., Clemens W., et al.; ISBN 3898641511 (February, 2002)


    Programmieren mit Ruby. Handbuch für den pragmatischen

Dave T. & Andy H.
Addison-Wesley, 2002; ISBN: 382731965X.
A German translation of the “Pickaxe” (Programming Ruby).

Pickaxe translation by Juergen Katins:

Search past postings to comp.lang.ruby or the ruby-lang mail list
(which have been mirrored to each other since mid-2000):

Local Ruby users and groups in your area:

2 About comp.lang.ruby

2.1 Tell me about comp.lang.ruby

comp.lang.ruby was officially approved in early May, 2000.
(Conrad Schneiker, the former maintainer of this FAQ, was
responsible for the "net paperwork" of creating this group.)
Here is the official charter:

    CHARTER: comp.lang.ruby

    The comp.lang.ruby newsgroup is devoted to discussions of the
    Ruby programming language and related issues.

    Examples of relevant postings include, but are not limited
    to, the following subjects:

    - Bug reports
    - Announcements of software written with Ruby
    - Examples of Ruby code
    - Suggestions for Ruby developers
    - Requests for help from new Ruby programmers

    The newsgroup is not moderated.  Binaries are prohibited
    (except the small PGP type). Advertising is prohibited (except
    for announcements of new Ruby-related products).


2.2 Tell me the posting guidelines for comp.lang.ruby.

(You should also follow these guidelines for the ruby-list mail
list, since it is mirrored to comp.lang.ruby.)

(1) ALWAYS be friendly, considerate, tactful, and tasteful.  We
    want to keep this forum hospitable to the growing ranks of
    newbies, very young people, and their teachers, as well as
    cater to fire breathing wizards.

(2) Keep your content relevant and easy to follow. Try to keep
    your content brief and to the point, but also try to include
    all relevant information.

    (a) The general format guidelines (aka USENET Netiquette) are
        matters of common sense and common courtesy that make life
        easier for 3rd parties to follow along (in real time or
        when perusing archives):

        - PLEASE NOTE! Include quoted text from previous posts
          *BEFORE* your responses. And *selectively* quote as much
          as is relevant.
        - Use *plain* text; don't use HTML, RTF, or Word. Most
          mail or newsreader programs have an option for this; if
          yours doesn't, get a (freeware) program or use a
          web-based service that does.
        - Include examples from files as *in-line* text; don't
          use attachments.

    (b) If reporting a problem, give *all* the relevant
        information the first time; this isn't the psychic friends
        newsgroup.    When appropriate, include:

        - The version of Ruby. ("ruby -v")
        - The compiler name and version used to build Ruby.
        - The OS type and level. ("uname -a")
        - The actual error messages.
        - An example (preferably simple) that produces the

(3) Make the subject line maximally informative, so that people
    who should be interested will read your post and so that people
    who wouldn't be interested can easily avoid it.

    *Usefully* describe the contents of your post:

        This is OK:

            "How can I do x with y on z?"
            "Problem: did x, expected y, got z."
            "BUG: doing x with module y crashed z."

        This is *NOT* OK:

            "Please help!!!"
            "Newbie question"
            "Need Ruby guru to tell me what's wrong"

  These prefixes have become common for subject lines:

            ANN:  (for announcements)
      BUG:  (for bug reports)
      OT:   (for off-topic, if you must post off-topic)

(4) Finally, be considerate: don't be too lazy. If you are
    seeking information, first make a reasonable effort to look it
    up. As appropriate, check the Ruby home page, check the Ruby

FAQ and other documentation, use to search past
comp.lang.ruby postings, and so on.

2.3 Tell me about the prolific Matz poster.

Matz (aka Yukihiro M.) is the wizard who created Ruby for
us, so be nice to him. He is very busy, so be patient when asking
questions. See the Ruby home page to find out more about him and
his work. I (Conrad Schneiker) founded comp.lang.ruby at his
suggestion. Contrary to lots of skepticism, it was approved on
the first attempt, with 200 yes votes.

2.4 How do the mailing list and newsgroup interrelate?

The mailing list is older. When the newsgroup was created, they
diverged. In mid-2001, Dave T. created a two-way gateway
that would "mirror" the newsgroup to the list and vice versa.
(This was accomplished in 200 lines of Ruby code.) It is not
perfect; because of variability in the news feed, sometimes
messages are dropped or duplicated.

The online archive of the mailing list therefore includes most
of the traffic on the newsgroup, excluding the posts that were
made before the creation of the gateway.

Note: Spam or other inappropriate messages are NOT the
responsibility of Dave T., who maintains the gateway. He
does everything in his power to deal with this issue. Do NOT
report spam to his ISP merely because the messages come from
his server.

2.5 What are these 6-digit message numbers?

Historically, every item on the mailing list had a subject
starting with a string like: [ruby-talk:99999]

The message numbers were convenient since they were strictly
serial and formed a good way to refer to a past message. But
they interfered with threading; Matz removed them after the
matter was put to a vote in early 2002.

The news header still refers to this number, should anyone
wish to retrieve it. On the mailing list this number can
now be found in the X-Mail-Count: header.

You can point to a specific message by appending it onto the URL; i.e. will refer
to message 12345. (NOTE: The above was true, but is not
currently working.)

2.6 What is “POLS”?

POLS is an abbreviation for "Principle of Least Surprise" (also
called the Law of Least Astonishment).

This term certainly did not originate in the Ruby community, but
it has been frequently used there -- even overused or abused at
times. After all, *every* language or software system seeks at
some level to adhere to this principle. Is any system designed
to be unintuitive?

It is inappropriate to invoke POLS as a "magic word" when one's
individual expectations are not met. Ruby continues to evolve,
and Matz often makes changes based on people wishes, needs, or
suggestions. But he cannot be bribed or threatened. Make
suggestions if you wish, but think twice before mentioning POLS.
  1. Anything else?

    If you are new to Ruby (or haven’t previously taken the Ruby U.
    Survey), please take a moment to anonymously tell us about your
    programming background and about your Ruby-related interests. The
    results will be reported back to the Ruby community from time to
    time. This helps us do a better job of helping each other, and to
    more effectively expand the Ruby community for our mutual benefit.
    The survey is at:

    This FAQ was originally produced by Conrad Schneiker.
    It is now maintained by Hal F. ([email protected]).
    I’m interested in corrections and suggestions, but remember that
    the purpose of this FAQ is to be a brief and simple introduction
    for new comp.lang.ruby readers.

    In closing, one of the reasons that Ruby was designed to be
    relatively simple, uniform, yet very powerful was to make serious
    programming (among other kinds) fun. We hope you will help us
    keep comp.lang.ruby fun as well. Enjoy.