diff --git a/bg/about/index.md b/bg/about/index.md
index 8282b03a37..5f34eb8214 100644
--- a/bg/about/index.md
+++ b/bg/about/index.md
@@ -156,11 +156,8 @@ Ruby притежава множество други черти, като ня
 * Позволява динамично зареждане на разширителни външни библиотеки в
   случай, че операционната система го позволява.
 
-* Позволява програмиране с нишки, независимо от операционната система.
-
 * Ruby е преносим език: създаден предимно на GNU/Linux, но работи под
-  много UNIX-базирани операционни системи, macOS,
-  Windows, DOS, BeOS, OS/2 и др.
+  много UNIX-базирани операционни системи, macOS, и Windows.
 
 ### Други имплементации на Ruby
 
@@ -181,11 +178,6 @@ Ruby притежава множество други черти, като ня
 * [mruby][mruby] е лека и бърза имплементация на Ruby, която може да бъде
   вградена и използвана в приложения. Разработва се от екип начело със
   създателя на Ruby Yukihiro "Matz" Matsumoto.
-* [IronRuby][ironruby] е имплементация, интегрирана с .NET
-  Framework.
-* [MagLev][maglev] e "бърза, стабилна Ruby имплементация".
-* [Cardinal][cardinal] e “Ruby компилатор за виртуалната машина
-  [Parrot][parrot]” (Perl 6).
 
 ### Референции
 
@@ -208,9 +200,5 @@ Ruby притежава множество други черти, като ня
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/de/about/index.md b/de/about/index.md
index e5de971735..328a55e2b3 100644
--- a/de/about/index.md
+++ b/de/about/index.md
@@ -180,13 +180,9 @@ Ruby hat eine Fülle weiterer Features, unter ihnen folgende:
 * Ruby kann Erweiterungen dynamisch laden, wenn es das Betriebssystem
   erlaubt.
 
-* Ruby hat plattformunabhängige Threads. Damit steht unter allen Systemen,
-  die Ruby unterstützen, auch Multithreading zur Verfügung, sogar unter
-  MS-DOS!
-
 * Ruby ist in hohem Maße portabel: Es wird vorrangig auf GNU/Linux
   entwickelt, arbeitet aber auf vielen UNIX-Varianten wie macOS,
-  auf Windows, DOS, BeOS, OS/2, usw.
+  und auf Windows.
 
 ### Alternative Ruby-Implementierungen
 
@@ -213,12 +209,6 @@ Hier ist eine Liste:
   gelinkt und in Anwendungen eingebunden werden kann.
   Die Entwicklung von mruby wird von Yukihiro “Matz” Matsumoto geleitet,
   dem Schöpfer von Ruby.
-* [IronRuby][ironruby] integriert sich gut in die .NET-Plattform.
-* [MagLev][maglev] definiert sich selbst als „eine schnelle, stabile
-  Ruby-Implementierung mit integrierter Objektpersistenz und verteiltem
-  Shared Cache“.
-* [Cardinal][cardinal] ist ein „Ruby-Compiler für die
-  [Parrot][parrot] Virtual Machine“ (Perl 6).
 
 ### Referenzen
 
@@ -242,9 +232,5 @@ November 2001.
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/en/about/index.md b/en/about/index.md
index 2cb827b07c..3957acecf3 100644
--- a/en/about/index.md
+++ b/en/about/index.md
@@ -168,12 +168,8 @@ Ruby has a wealth of other features, among which are the following:
 
 * Ruby can load extension libraries dynamically if an OS allows.
 
-* Ruby features OS independent threading. Thus, for all platforms on
-  which Ruby runs, you also have multithreading, regardless of if the OS
-  supports it or not, even on MS-DOS!
-
 * Ruby is highly portable: it is developed mostly on GNU/Linux, but
-  works on many types of UNIX, macOS, Windows, DOS, BeOS, OS/2, etc.
+  works on many types of UNIX, macOS, and Windows.
 
 ### Other Implementations of Ruby
 
@@ -198,12 +194,6 @@ Here’s a list:
 * [mruby][mruby] is a lightweight implementation of the Ruby language
   that can be linked and embedded within an application.
   Its development is led by Ruby’s creator Yukihiro “Matz” Matsumoto.
-* [IronRuby][ironruby] is an implementation “tightly integrated with the .NET
-  Framework”.
-* [MagLev][maglev] is “a fast, stable, Ruby implementation with integrated
-  object persistence and distributed shared cache”.
-* [Cardinal][cardinal] is a “Ruby compiler for [Parrot][parrot] Virtual Machine”
-  (Perl 6).
 
 For a more complete list, see [Awesome Rubies][awesome-rubies].
 
@@ -230,11 +220,7 @@ For a more complete list, see [Awesome Rubies][awesome-rubies].
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [truffleruby]: https://github.com/oracle/truffleruby
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
 [awesome-rubies]: https://github.com/planetruby/awesome-rubies
diff --git a/en/documentation/faq/1/index.md b/en/documentation/faq/1/index.md
index 1d03ad67e0..162a0d26c9 100644
--- a/en/documentation/faq/1/index.md
+++ b/en/documentation/faq/1/index.md
@@ -61,8 +61,7 @@ Ruby features:
 * Iterators and closures,
 * Garbage collection,
 * Dynamic loading (depending on the architecture),
-* High transportability (runs on various Unices, Windows, DOS, macOS, OS/2,
-  Amiga, and so on).
+* High transportability (runs on various Unices, Windows, and macOS).
 
 ### Show me some Ruby code!
 
diff --git a/en/documentation/faq/3/index.md b/en/documentation/faq/3/index.md
index 7d740be207..c086383218 100644
--- a/en/documentation/faq/3/index.md
+++ b/en/documentation/faq/3/index.md
@@ -47,7 +47,7 @@ or [Downloads](/en/downloads/) page.
 
 Ruby is developed under Linux, and is written in fairly straightforward C.
 It runs under Linux and other UNIX-like operating systems, macOS,
-Windows, DOS, BeOS, Amiga, Acorn Risc OS, and OS/2.
+and Windows.
 
 ### Where can I get Ruby sources?
 
diff --git a/en/documentation/faq/9/index.md b/en/documentation/faq/9/index.md
index c89a09b315..a927b65a17 100644
--- a/en/documentation/faq/9/index.md
+++ b/en/documentation/faq/9/index.md
@@ -329,7 +329,6 @@ Thread and fork have the following characteristics:
 * `fork` is slow, `thread` is not.
 * `fork` does not share the memory space.
 * `thread` does not cause thrashing.
-* `thread` works on DOS.
 * When `thread` gets in a deadlock, the whole process stops.
 * `fork` can take advantage of pauses waiting for I/O to complete,
   `thread` does not (at least not without some help).
diff --git a/es/about/index.md b/es/about/index.md
index c3e52af870..61e587ca47 100644
--- a/es/about/index.md
+++ b/es/about/index.md
@@ -178,14 +178,8 @@ encuentran las siguientes:
 * Puede cargar bibliotecas de extensión dinámicamente si lo permite el
   sistema operativo.
 
-* Tiene manejo de hilos (threading) independiente del sistema operativo.
-  De esta forma, tienes soporte multi-hilo en todas las plataformas en
-  las que corre Ruby, sin importar si el sistema operativo lo soporta o
-  no, ¡incluso en MS-DOS!
-
 * Ruby es fácilmente portable: se desarrolla mayoritariamente en
-  GNU/Linux, pero corre en varios tipos de UNIX, macOS,
-  Windows, DOS, BeOS, OS/2, etc.
+  GNU/Linux, pero corre en varios tipos de UNIX, macOS, y Windows.
 
 ### Otras implementaciones de Ruby
 
@@ -200,10 +194,6 @@ Aquí hay una lista:
 * [TruffleRuby][truffleruby] una implementación de Ruby de alto rendimiento sobre GraalVM.
 * [mruby][mruby] es una implementación ligera del lenguaje Ruby que se puede vincular e incrustar dentro de una aplicación.
 Su desarrollo es liderado por el creador de Ruby, Yukihiro "Matz" Matsumoto.
-* [IronRuby][ironruby] es una implementación "estrechamente integrada con el marco de trabajo .NET".
-* [MagLev][maglev] es "una implementación de Ruby rápida y estable con persistencia de objetos integrada y caché compartida distribuida".
-* [Cardinal][cardinal] es un "compilador Ruby para la máquina virtual [Parrot][parrot]”
-  (Perl 6).
 
 Para una lista más completa, vea [Awesome Rubies][awesome-rubies].
 
@@ -230,11 +220,7 @@ del 2003.
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [truffleruby]: https://github.com/oracle/truffleruby
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
 [awesome-rubies]: https://github.com/planetruby/awesome-rubies
diff --git a/fr/about/index.md b/fr/about/index.md
index ef8bab2e8e..cf50901c20 100644
--- a/fr/about/index.md
+++ b/fr/about/index.md
@@ -198,7 +198,7 @@ parmi lesquelles on peut citer…
   le système d’exploitation le permet ;
 * une très grande portabilité : développé majoritairement sous
   GNU/Linux, Ruby fonctionne aussi sur une grande part des UNIX, macOS,
-  Windows, DOS, BeOS, OS/2, etc.
+  et Windows.
 
 ### Références
 
diff --git a/id/about/index.md b/id/about/index.md
index 061b2c5273..fba7dede24 100644
--- a/id/about/index.md
+++ b/id/about/index.md
@@ -182,14 +182,8 @@ Ruby kaya fitur, antara lain sebagai berikut:
 * Ruby bisa memuat *extension library* secara dinamis jika sistem operasi
   mengizinkan.
 
-* Ruby menyediakan fitur OS *threading* yang independen. Maka, untuk
-  semua *platform* dimana Ruby berjalan, Anda juga punya *multithreading*,
-  terlepas dari apakah sistem operasi mendukung *multithreading* atau
-  tidak, bahkan pada MS-DOS sekalipun!
-
 * Ruby sangat *portable*: Ruby kebanyakan dikembangkan di GNU/Linux,
-  tetapi juga berjalan di banyak tipe UNIX, macOS,
-  Windows, DOS, BeOS, OS/2, dan lain-lain.
+  tetapi juga berjalan di banyak tipe UNIX, macOS, dan Windows.
 
 ### Implementasi Lain dari Ruby
 
@@ -213,12 +207,6 @@ Berikut ini daftarnya:
   yang memiliki performa tinggi.
 * [mruby][mruby] adalah sebuah implementasi *lightweight* dari bahasa Ruby
   yang dapat dihubungkan dan ditanamkan dengan sebuah aplikasi.
-* [IronRuby][ironruby] adalah sebuah implementasi “tightly integrated with
-  the .NET Framework”.
-* [MagLev][maglev] adalah “a fast, stable, Ruby implementation with integrated
-  object persistence and distributed shared cache”.
-* [Cardinal][cardinal] adalah “Ruby compiler for [Parrot][parrot] Virtual
-  Machine” (Perl 6).
 
 Untuk daftar lebih lengkapnya, lihat [Awesome Rubies][awesome-rubies].
 
@@ -246,11 +234,7 @@ di Ruby, dalam Bahasa Inggris), 22 Desember 2003.
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [sigil]: http://en.wikipedia.org/wiki/Sigil_%28computer_programming%29
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [truffleruby]: https://github.com/oracle/truffleruby
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
 [awesome-rubies]: https://github.com/planetruby/awesome-rubies
diff --git a/id/community/index.md b/id/community/index.md
index da349b98a9..2210eab140 100644
--- a/id/community/index.md
+++ b/id/community/index.md
@@ -61,7 +61,7 @@ untuk memulai petualangan Anda:
   Indonesia, baik yang bertempat tinggal di seluruh penjuru Indonesia,
   juga orang Indonesia yang sedang tinggal di luar negeri). Berdiskusi
   tentang Ruby berikut semua varian-varian Ruby (seperti JRuby,
-  Rubinius, XRuby, IronRuby, dan lain sebagainya) termasuk juga
+  Rubinius, XRuby, dan lain sebagainya) termasuk juga
   aplikasi-aplikasi yang dibuat dengan Ruby seperti Rails. Anda bisa
   bergabung ke grup [Slack][ruby-id-slack] Ruby Indonesia untuk saling berbagi
   dengan komunitas.
diff --git a/id/news/_posts/2008-04-07-fresh-overview-dari-rubinius.md b/id/news/_posts/2008-04-07-fresh-overview-dari-rubinius.md
index b0c7c67a7e..431725737c 100644
--- a/id/news/_posts/2008-04-07-fresh-overview-dari-rubinius.md
+++ b/id/news/_posts/2008-04-07-fresh-overview-dari-rubinius.md
@@ -26,5 +26,5 @@ Sumber: [Ruby Inside-A Fresh Overview of Rubinius][3]
 
 
 [1]: http://programblings.com/2008/04/01/rubinius-for-the-layman-part-1-rubies-all-the-way-down/
-[2]: http://rubini.us/
+[2]: https://github.com/rubinius/rubinius
 [3]: http://www.rubyinside.com/a-fresh-overview-of-rubinius-835.html
diff --git a/id/news/_posts/2008-05-19-rubinius-on-rails-rubinius-telah-menjadi-implementasi-ruby-ketiga-yang-menjalankan-rails.md b/id/news/_posts/2008-05-19-rubinius-on-rails-rubinius-telah-menjadi-implementasi-ruby-ketiga-yang-menjalankan-rails.md
index f3ebad98e6..ca72d3b284 100644
--- a/id/news/_posts/2008-05-19-rubinius-on-rails-rubinius-telah-menjadi-implementasi-ruby-ketiga-yang-menjalankan-rails.md
+++ b/id/news/_posts/2008-05-19-rubinius-on-rails-rubinius-telah-menjadi-implementasi-ruby-ketiga-yang-menjalankan-rails.md
@@ -26,7 +26,7 @@ Run Rails][6]
 
 
 [1]: http://twitter.com/evanphx
-[2]: http://rubini.us/
+[2]: https://github.com/rubinius/rubinius
 [3]: http://blog.fallingsnow.net/2008/05/17/rails-on-rubinius/
 [4]: http://www.chadfowler.com/2008/5/17/ruby-on-rails-on-rubinius
 [5]: http://www.ironruby.net/
diff --git a/it/about/index.md b/it/about/index.md
index 44a1a78e3b..e610c95e54 100644
--- a/it/about/index.md
+++ b/it/about/index.md
@@ -179,14 +179,8 @@ Ruby è in grado di offrire una marea di altre funzionalità, tra cui:
 * Ruby è in grado di caricare dinamicamente delle librerie di estensione,
   se il sistema operativo lo permette.
 
-* Ruby offre funzionalità di threading indipendenti dal sistema
-  operativo. In questo modo si può avere multithreading su tutte le
-  piattaforme in grado di eseguire Ruby, indipendentemente dal fatto che
-  il sistema operativo lo supporti o meno, anche in DOS!
-
 * Ruby è altamente portatile: è sviluppato principalmente su GNU/Linux,
-  ma funziona su molte varianti di UNIX, macOS,
-  Windows, DOS, BeOS, OS/2, ecc.
+  ma funziona su molte varianti di UNIX, macOS, e Windows.
 
 ### Riferimenti
 
diff --git a/ja/about/index.md b/ja/about/index.md
index 895367cb33..aa5311b9a9 100644
--- a/ja/about/index.md
+++ b/ja/about/index.md
@@ -153,11 +153,8 @@ Rubyは次に示すような豊富な機能を持っています。
 
 * OSが許すなら、Rubyは動的なライブラリ拡張をロードすることもできます。
 
-* RubyはOSに依存しないスレッド機構を備えています。これによって、Rubyが動作するすべてのプラットフォーム上で、
-  OSのサポートなしに(MS-DOSだとしても！)マルチスレッド処理を扱えます。
-
 * Rubyにはとても高い可搬性があります。Rubyは主にGNU/Linux上で開発されていますが、
-  UNIX、macOS、Windows、DOS、BeOS、OS/2など、多くのOSで動作します。
+  UNIX、macOS、Windows、多くのOSで動作します。
 
 ### さまざまなRuby処理系
 
@@ -174,13 +171,6 @@ MRI以外のRuby処理系には以下のようなものがあります。
 * [mruby][mruby]はRubyの軽量実装です。アプリケーションにリンクし、組み込むことができます。Rubyの作者であるまつもと ゆきひろ氏によって開発が進められています。
 * [truffleruby][truffleruby]はGraalVM上に構築された高速なRuby実装です。
 
-#### 以下のバージョンはここ数年ほとんどまたは全く更新されていませんが、引き続き利用可能です。
-
-* [Rubinius][rubinius]は「Rubyで書かれたRuby」です。LLVM上に構築されています。LLVMは他の言語も構築されるよくできた仮想マシンです。
-* [IronRuby][ironruby]は、.Netフレームワークにしっかりと統合されたRuby処理系です。
-* [MagLev][maglev]は、オブジェクトの永続化と分散共有キャッシュを持った、高速で安定したRuby処理系です。
-* [Cardinal][cardinal]はPerl6用の仮想マシンである[Parrot][parrot]上のRubyコンパイラです。
-
 ### 参照リンク
 
 <sup>1</sup> Matz, ruby-talk メーリングリスト上での会話, [2000年5月12日][blade]。
@@ -200,10 +190,5 @@ MRI以外のRuby処理系には以下のようなものがあります。
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
 [mruby]: http://www.mruby.org/
 [truffleruby]: https://github.com/oracle/truffleruby
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/ko/about/index.md b/ko/about/index.md
index d5fc1a4763..98b2a1a0fe 100644
--- a/ko/about/index.md
+++ b/ko/about/index.md
@@ -132,10 +132,7 @@ Ruby는 개발자의 편의를 위해 많은 기능을 제공합니다. 그 중
 
 * OS가 지원한다면 확장 기능을 동적으로 로드할 수 있습니다.
 
-* Ruby는 운영체제에 의존하지 않는 스레딩 기능을 제공합니다. 그리고 이는 Ruby가 동작하는 모든 플랫폼에 적용되어서 스레드를
-  지원하지 않는 MS-DOS에서도 다중 스레드 프로그램을 작성할 수 있습니다.
-
-* Ruby는 이식성이 매우 높습니다. 대부분 GNU Linux에서 개발되었지만 대부분의 UNIX, macOS, Windows, DOS, BeOS, OS/2 등에서 동작합니다.
+* Ruby는 이식성이 매우 높습니다. 대부분 GNU Linux에서 개발되었지만 대부분의 UNIX, macOS, Windows 등에서 동작합니다.
 
 ### Ruby의 다른 구현체들
 
@@ -153,9 +150,6 @@ MRI가 지원하지 않는 특별한 기능을 가지거나 합니다.
   Rubinius는 다른 언어 역시 구축된 멋진 가상 머신 위에서 활동합니다.
 * [mruby][mruby]는 Ruby의 경량 구현체로 애플리케이션 안에 링크되거나 포함시킬 수 있습니다.
   Ruby의 창시자인 유키히로 “Matz” 마츠모토가 개발을 이끌고 있습니다.
-* [IronRuby][ironruby]는 “.NET Framework과 강력하게 통합된” 구현체입니다.
-* [MagLev][maglev]는 “통합된 개체 지속성과 분산 공유 캐시를 가진 빠르고, 안정적인 Ruby 구현체”입니다.
-* [Cardinal][cardinal]는 “[Parrot][parrot] 가상 기기을 위한 Ruby 컴파일러”(Perl 6)입니다.
 
 ### 참조
 
@@ -180,9 +174,5 @@ MRI가 지원하지 않는 특별한 기능을 가지거나 합니다.
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/pl/about/index.md b/pl/about/index.md
index 8fc6e8dcd3..e9b8ff1716 100644
--- a/pl/about/index.md
+++ b/pl/about/index.md
@@ -177,13 +177,8 @@ Ruby posiada bogactwo innych właściwości, niektóre z nich to:
 * Jeśli system operacyjny na to pozwala, Ruby pozwala na dynamiczne
   ładowanie bibliotek.
 
-* Ruby posiada wątki, które są niezależne od systemu operacyjnego. To
-  znaczy, że są one dostępne na każdej platformie, niezależnie od tego,
-  czy sama platforma wspiera wątki, można ich używać nawet w MS-DOS!
-
 * Ruby jest bardzo przenośny: rozwijany głównie na platformie GNU/Linux,
-  ale może być używany na wielu typach UNIXów, macOS,
-  Windows, DOS, BeOS, OS/2, itd.
+  ale może być używany na wielu typach UNIXów, macOS, Windows, itd.
 
 ### Inne implementacje Rubiego
 
@@ -203,12 +198,6 @@ Tu jest lista:
   języki.
 * [mruby][mruby] jest lekką implementacją języka Ruby, która może być połączona
   i osadzona w aplikacji.
-+  Its development is lead by Ruby’s creator Yukihiro “Matz” Matsumoto.
-* [IronRuby][ironruby] jest implementacją “ściśle zintegrowaną z frameworkiem .NET”.
-* [MagLev][maglev] jest “szybką, stabilną, implementacją Rubiego ze zintegrowaną
-  trwałością obiektów i rozproszonym wpsółdzielonym cachem”.
-* [Cardinal][cardinal] jest “kompilatorem Rubiego dla [Parrot][parrot] Virtual Machine”
-  (Perl 6).
 
 ### Odnośniki
 
@@ -231,9 +220,5 @@ Tu jest lista:
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/pt/about/index.md b/pt/about/index.md
index 2c14fa521f..9bf635801e 100644
--- a/pt/about/index.md
+++ b/pt/about/index.md
@@ -181,14 +181,9 @@ seguintes:
 * O Ruby pode carregar bibliotecas de extensão (_extension libraries_)
   dinamicamente se o Sistema Operacional permitir.
 
-* O Ruby tem um sistema de _threading_ independente do Sistema Operacional.
-  Portanto, para todas as plataformas nas quais o Ruby roda, temos
-  _multithreading_ independentemente de o Sistema Operacional suportar ou
-  não, temos _multithreading_ até em MS-DOS!
-
 * O Ruby é altamente portável: é desenvolvido principalmente em ambiente
   GNU/Linux, mas trabalha em muitos tipos de ambientes UNIX, macOS,
-  Windows, DOS, BeOS, OS/2, etc.
+  Windows, etc.
 
 ### Outras Implementações do Ruby
 
@@ -212,12 +207,6 @@ Segue uma lista:
 * [mruby][mruby] é uma implementação leve da linguagem Ruby que pode ser
   vinculada e embutida em uma aplicação. Seu desenvolvimento é conduzido
   pelo criador do Ruby, Yukihiro “Matz” Matsumoto.
-* [IronRuby][ironruby] é uma implementação “fortemente integrada ao .NET
-  Framework”.
-* [MagLev][maglev] é “uma implementação rápida e estável do Ruby, com
-  persitência de objetos integrada e cache compartilhado distribuído”.
-* [Cardinal][cardinal] é um “compilador Ruby para a Máquina Virtual
-  [Parrot][parrot]” (Perl 6).
 
 ### Referências
 
@@ -242,9 +231,5 @@ Nov. 2001.
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/ru/about/index.md b/ru/about/index.md
index 47e99ad401..632369bc65 100644
--- a/ru/about/index.md
+++ b/ru/about/index.md
@@ -177,15 +177,9 @@ Ruby полон другими особенностями и конструкц
 * Ruby может подгружать сторонние библиотеки динамически, если позволяет
   операционная система.
 
-* В Ruby реализованы независимые от операционной системы потоки.
-  Таким образом, на любых платформах, где вы запускаете Ruby, вы также
-  можете использовать многопоточность, не зависимо от того,
-  поддерживает ли данная система потоки или нет. Вы можете использовать
-  возможности многопоточности даже в MS-DOS!
-
 * Ruby отличается высокой переносимостью: он был разработан большей
   частью на GNU/Linux, но работает на многих типах UNIX, macOS,
-  Windows, DOS, BeOS, OS/2, и так далее.
+  Windows.
 
 ### Другие реализации Ruby
 
@@ -207,13 +201,6 @@ Ruby как язык имеет несколько разных реализац
 * [mruby][mruby] — это легковесная реализация Ruby, которая может быть
   подключена и встроена в приложение. Возглавляет разработку mruby создатель
   языка Ruby, Юкихиро Мацумото (Yukihiro Matsumoto), известного под псевдонимом Мац (Matz).
-* [IronRuby][ironruby] — это реализация «тесно интегрированная с .NET
-  Framework».
-* [MagLev][maglev] — это «быстрая, стабильная реализация Ruby с
-  интегрированным долговременным хранением объектов и распределенным открытым
-  кешем".
-* [Cardinal][cardinal] — это «компилятор Ruby для виртуальной машины [Parrot][parrot]»
-  (Perl 6).
 
 ### Ссылки
 
@@ -238,9 +225,5 @@ Ruby как язык имеет несколько разных реализац
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/tr/about/index.md b/tr/about/index.md
index 98fffb63c3..b0e9d1f111 100644
--- a/tr/about/index.md
+++ b/tr/about/index.md
@@ -165,13 +165,8 @@ bahsedilmiştir:
 * İşletim sistemi izin verdiği sürece harici dinamik kütüphaneler
   yükleyebilirsiniz.
 
-* Ruby işletim sisteminden bağımsız iş parçacığı özelliği sunar.Yani
-  işletim sisteminin desteklemesine bakmaksızın, MS-DOS üzerinde olsanız
-  bile çoklu iş parçacıkları kullanabilirsiniz!
-
 * Ruby yüksek taşınabilirliğe sahiptir. GNU/Linux üzerinde geliştirilmiş
-  olsa dahi, UNIX’in bir çok çeşidi, macOS,
-  Windows, DOS, BeOS, OS/2, vb. üzerinde çalışmaktadır.
+  olsa dahi, UNIX’in bir çok çeşidi, macOS ve Windows üzerinde çalışmaktadır.
 
 ### Ruby'nin Diğer Gerçeklemeleri
 
@@ -187,9 +182,6 @@ Bunlar belirli durumlarda kullanışlıdır, diğer dil ya da ortamlara fazladan
 * [TruffleRuby][truffleruby], GraalVM'in üstünde çalışan yüksek performanslı bir Ruby gerçeklemesidir.
 * [mruby][mruby], bir uygulamaya bağlanıp gömülebilen hafif bir Ruby gerçeklemesidir.
   Geliştirilmesine Ruby'nin yaratıcısı Yukihiro “Matz” Matsumoto tarafından önderlik edilmektedir.
-* [IronRuby][ironruby], “.NET Web Çatısı'yla sıkı sıkıya bağlı” bir gerçeklemedir.
-* [MagLev][maglev], “bütünleşik nesne sürekliliği ve dağıtılmış paylaşılan önbellekli hızlı, kararlı bir Ruby gerçeklemesidir”.
-* [Cardinal][cardinal], [Parrot][parrot] Sanal Makinesi için bir Ruby derleyicisidir” (Perl 6).
 
 Daha tam bir liste için, [Müthiş Ruby'ler][awesome-rubies]e bakın.
 
@@ -213,11 +205,7 @@ Daha tam bir liste için, [Müthiş Ruby'ler][awesome-rubies]e bakın.
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [truffleruby]: https://github.com/oracle/truffleruby
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
 [awesome-rubies]: https://github.com/planetruby/awesome-rubies
diff --git a/vi/about/index.md b/vi/about/index.md
index 45f3cb7b8e..b390ab79c5 100644
--- a/vi/about/index.md
+++ b/vi/about/index.md
@@ -162,12 +162,8 @@ phần mềm để sử dụng như là một ngôn ngữ scripting. Một giao
 
 * Ruby có thể đọc các thư viện mở rộng (extension library) kiểu động nếu OS cho phép.
 
-* Ruby có threading độc lập với cả hệ điều hành. Thế nên, tất cả nền tảng khác
-mà Ruby chạy trên sẽ có multithreading bất kể hệ đấy có hỗ trợ hay không. Ngay
-cả MSDOS còn hỗ trợ!
-
 * Ruby rất dễ port: nó được phát triển chủ yếu cho GNU/Linux, nhưng có làm việc
-với các hệ UNIX khác, như macOS, Windows, DOS, BeOS, OS/2, vân vân.
+với các hệ UNIX khác, như macOS, Windows, vân vân.
 
 ### Tham khảo
 
diff --git a/zh_cn/about/index.md b/zh_cn/about/index.md
index d13b8cf60f..5470785f8c 100644
--- a/zh_cn/about/index.md
+++ b/zh_cn/about/index.md
@@ -110,9 +110,7 @@ Ruby 还有其他众多特性，下面列举一些：
 
 * 如果操作系统允许，Ruby 可以动态加载扩展库。
 
-* Ruby 提供不依赖操作系统的线程。所以，不管操作系统是否支持，Ruby 支持的所有操作系统都可以使用多线程，甚至是 MS-DOS!
-
-* Ruby 高度可移植：它主要在 GNU/Linux 上开发，但也支持很多类型的 UNIX，以及 macOS，Windows，DOS，BeOS，OS/2 等。
+* Ruby 高度可移植：它主要在 GNU/Linux 上开发，但也支持很多类型的 UNIX，以及 macOS，Windows 等。
 
 ### Ruby 的其他实现
 
@@ -123,9 +121,6 @@ Ruby 还有其他众多特性，下面列举一些：
 * [JRuby][jruby] 是基于 JVM（Java Virtual Machine）的 Ruby 实现，利用了 JVM 中优秀的 JIT 编译器、垃圾回收程序、并发线程、工具生态系统和大量的库。
 * [Rubinius][rubinius] 是用“Ruby 编写的 Ruby”。构建于 LLVM 之上，Rubinius 跑在一个很灵活的虚拟机上，别的语言也可以构建于这个虚拟机上。
 * [mruby][mruby] 是 Ruby 语言的轻量级实现，可以链接或嵌入到程序之中。mruby 由 Ruby 的创建者松本行弘（Matz）领导开发。
-* [IronRuby][ironruby] 是一个“与 .NET 框架紧密集成”的实现。
-* [MagLev][maglev] 是“一个快速、稳定的 Ruby 实现，支持集成对象持久化和分布式共享缓存”。
-* [Cardinal][cardinal] 是一个“为 [Parrot][parrot] 虚拟机 （Perl 6）编写的 Ruby 编译器”。
 
 ### 参考资料
 
@@ -147,9 +142,5 @@ Ruby 还有其他众多特性，下面列举一些：
 [artima]: http://www.artima.com/intv/closures2.html
 [tiobe]: http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
 [jruby]: http://jruby.org
-[rubinius]: http://rubini.us
+[rubinius]: https://github.com/rubinius/rubinius
 [mruby]: http://www.mruby.org/
-[ironruby]: http://www.ironruby.net
-[maglev]: http://maglev.github.io
-[cardinal]: https://github.com/parrot/cardinal
-[parrot]: http://parrot.org
diff --git a/zh_tw/about/index.md b/zh_tw/about/index.md
index b2f0240cda..4055cf022f 100644
--- a/zh_tw/about/index.md
+++ b/zh_tw/about/index.md
@@ -110,9 +110,7 @@ Ruby 還具有以下的特點：
 
 * 如果作業系統支援，Ruby 可以動態的載入擴充函式庫。
 
-* Ruby 具有與作業系統無關的多線程（threading）能力。可以在所有可以執行 Ruby 的平台上都能夠達到多線程的目標，而不必管作業系統是否支援，就算是 MS-DOS 也行。
-
-* Ruby 具有高度的移植性：它大部份是在 GNU/Linux 上發展出來，但是可以執行於多種的作業系統如： UNIX、macOS、Windows、DOS、BeOS、OS/2 等。
+* Ruby 具有高度的移植性：它大部份是在 GNU/Linux 上發展出來，但是可以執行於多種的作業系統如： UNIX、macOS、Windows 等。
 
 ### 參考資料