Commons:An essay on the copyright status of IPAMonaPGothic, and its suitability for use in open source projects and on Wikimedia Commons

This essay is written something like a mathematical proof for simplicity.

Background

• 2channel is a Japanese-language textboard which launched in May 1999.
  • After a domain seizure in 2014, two sites claim to be the "real" 2channel: 5ch.net and 2ch.sc.
• The default font on the textboard and its direct predecessors was, and on its successors is, MS PGothic (
  ＭＳ Ｐゴシック
  ).
  • This is because Internet Explorer 4 defaulted to this font for Japanese text.
• The P stands for proportional.
• In a traditional CJK font, such as the regular MS Gothic (
  ＭＳ ゴシック
  ), a Latin character is equal to one half of a CJK character.
• In MS PGothic, however, the widths of Latin characters are more like a regular Latin font, such as Helvetica.
  • MS UI Gothic is similar, but narrower.
• A font is metrically-compatible if it can be replaced in a document without changing the sizes of the glyphs, nor their offsets, nor their kerning.
• MS PGothic is a proprietary font.
• Shift_JIS art is a form of digital art that relies on the metrics of MS PGothic to appear correctly.
  • It's a more expressive ASCII art.
• A font metrically-compatible with MS PGothic can also be used to correctly view Shift_JIS art.

IPA Fonts

• The Information-Technology Promotion Agency (IPA) (
  情報処理推進機構
  ) is an agency of the Japanese government.
• The IPA distributes fonts (IPA Fonts /
  IPAフォント
  ).
• The IPA Fonts are under the IPA Font License (IPAFL) (
  IPAフォントライセンスv1.0
  ), an OSI-approved license.

Law

• When licenses conflict, the more strict license prevails, as long as all licenses allow sublicensing, and are compatible.
• That is to say, a public domain file can become GPL without consent of the original author, but a GPL file cannot become public domain in the same way.

If a license is GPL-compatible, such as the Apache v2.0 license, for example, derivative works of it can be relicensed without knowledge or consent of original authors.

• The IPAFL is a "viral" license like the GNU GPLv2, but is not itself GPL-compatible according to the FSF.

The Recipient may create, use, reproduce and/or Redistribute a Derived Program under the terms stated above for the Licensed Program.

Predecessors of IPAMonaPGothic

• Mona (10 February 2001) is an X11 (BDF) font metrically-compatible with MS PGothic.
  • License: Public domain. (Per README.ascii)
• mona-outline (5 August 2003) is a TTF font metrically-compatible with MS PGothic.
  • License: Public domain. (Per README.ascii)
• Sazanami (2004) is a pixel and outline font © 1990–2003 by Wada Laboratory, the University of Tokyo and © 2003–2004 Electronic Font Open Laboratory.
  • License: 3-clause BSD license. (Per README of sazanami-20040629)

IPAMonaPGothic

• Jun Kobayashi modified the IPA Fonts, creating the IPA Mona Fonts
  IPAモナーフォント
  .
  • He also, according to him, used parts of Sazanami fonts, and Mona.
• Licenses conflict: 3-clause BSD, public domain, and IPAFL.
• The 3-clause BSD license is IPAFL-compatible; it contains no provision that's impossible to meet under the IPAFL.
• The IPAFL, therefore, prevails.
• As a viral license, IPAMonaPGothic is also under the terms of the IPAFL.
• IPAMonaPGothic is open source and suitable for use on Commons. QED