Embedded OpenType
Encyclopedia
Embedded OpenType fonts are a compact form of OpenType
fonts designed by Microsoft
for use as embedded fonts on web page
s. These files usually use the extension "
These font files can be created from existing TrueType
font files using Microsoft's Web Embedding Fonts Tool (WEFT), and other proprietary and open source software (see "External links" below).
The font files are made small in size by use of subsetting
(only including the needed characters), and by data compression
(LZ compression, part of Agfa's MicroType Express).
Simply including fonts in webpages might lead to unrestricted copying of copyrighted font files. Embedded OpenType includes features to discourage copying. Subsetting reduces the value of copying, as subsetted fonts will typically omit more than half of the characters. Other copy protection measures used are encryption
and a list of "trusted roots" at the source end, and a proprietary decrypting DLL at the receiving end.
If the embedded font is not available to the web page for any reason (missing font file, wrong keys in the file, non-support by the web browser), then the second-choice font specification is used, ensuring that the page should be readable even without the intended font.
Embedded OpenType is a proprietary standard supported exclusively by Internet Explorer
but was submitted to the W3C in 2007 as part of CSS3, which was rejected and resubmitted as a standalone submission March 18, 2008. The W3C team comment on the submission states that the "W3C plans to submit a proposal to the W3C members for a working group whose goal is to try and develop EOT into a W3C Recommendation."
's utility for generating embeddable web fonts
.
WEFT is used by webmaster
s to create 'font objects' that are linked to their web page
s so that users using Microsoft's Internet Explorer
web browser
will see the pages displayed in the font style contained within the font object.
WEFT scans the HTML
document file(s), the TrueType font file(s), and some additional parameters. It adjusts the HTML files and creates Embedded OpenType files for inclusion on the web site. These files usually use the extension "
WEFT can embed most fonts, but it will not embed fonts that have been designated as 'no embedding' fonts by their designers. WEFT may reject other fonts because problems have been identified.
Embedded fonts are widely used to generate non-English-language websites.
As of May 2010, the most recent version of the tool (WEFT 5.3.2) was released on 25 February 2003.
An open source alternative is "ttf2eot" http://code.google.com/p/ttf2eot/.
Microsoft PowerPoint 2007 and 2010 also generate .eot files with the ".fntdata" http://msdn.microsoft.com/en-us/library/ff529562(office.12).aspx extension when fonts are selected to be embedded in a presentation by the PowerPoint client application. These .eot files can be extracted from the ".pptx" file and used directly on web pages.
OpenType
OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType's basic structure and adding many intricate data structures for prescribing typographic behavior...
fonts designed by Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
for use as embedded fonts on web page
Web page
A web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext...
s. These files usually use the extension "
.eot".These font files can be created from existing TrueType
TrueType
TrueType is an outline font standard originally developed by Apple Computer in the late 1980s as a competitor to Adobe's Type 1 fonts used in PostScript...
font files using Microsoft's Web Embedding Fonts Tool (WEFT), and other proprietary and open source software (see "External links" below).
The font files are made small in size by use of subsetting
Subsetting
Subsetting is a concept used in research communities to describe the process of retrieving just the parts of large files which are of interest for a specific purpose. This occurs usually in a client—server setting, where the extraction of the parts of interest occurs on the server before the data...
(only including the needed characters), and by data compression
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
(LZ compression, part of Agfa's MicroType Express).
Simply including fonts in webpages might lead to unrestricted copying of copyrighted font files. Embedded OpenType includes features to discourage copying. Subsetting reduces the value of copying, as subsetted fonts will typically omit more than half of the characters. Other copy protection measures used are encryption
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
and a list of "trusted roots" at the source end, and a proprietary decrypting DLL at the receiving end.
If the embedded font is not available to the web page for any reason (missing font file, wrong keys in the file, non-support by the web browser), then the second-choice font specification is used, ensuring that the page should be readable even without the intended font.
Embedded OpenType is a proprietary standard supported exclusively by Internet Explorer
Internet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
but was submitted to the W3C in 2007 as part of CSS3, which was rejected and resubmitted as a standalone submission March 18, 2008. The W3C team comment on the submission states that the "W3C plans to submit a proposal to the W3C members for a working group whose goal is to try and develop EOT into a W3C Recommendation."
Web Embedding Fonts Tool
The Web Embedding Fonts Tool, or WEFT, is MicrosoftMicrosoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
's utility for generating embeddable web fonts
Web fonts
Web typography refers to the use of fonts on the World Wide Web. When HTML was first created, font faces and styles were controlled exclusively by the settings of each Web browser. There was no mechanism for individual Web pages to control font display until Netscape introduced the tag in 1995,...
.
WEFT is used by webmaster
Webmaster
A webmaster , also called a web architect, web developer, site author, or website administrator is a person responsible for maintaining one or many websites...
s to create 'font objects' that are linked to their web page
Web page
A web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext...
s so that users using Microsoft's Internet Explorer
Internet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
will see the pages displayed in the font style contained within the font object.
WEFT scans the HTML
HTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
document file(s), the TrueType font file(s), and some additional parameters. It adjusts the HTML files and creates Embedded OpenType files for inclusion on the web site. These files usually use the extension "
.eot".WEFT can embed most fonts, but it will not embed fonts that have been designated as 'no embedding' fonts by their designers. WEFT may reject other fonts because problems have been identified.
Embedded fonts are widely used to generate non-English-language websites.
As of May 2010, the most recent version of the tool (WEFT 5.3.2) was released on 25 February 2003.
An open source alternative is "ttf2eot" http://code.google.com/p/ttf2eot/.
Microsoft PowerPoint 2007 and 2010 also generate .eot files with the ".fntdata" http://msdn.microsoft.com/en-us/library/ff529562(office.12).aspx extension when fonts are selected to be embedded in a presentation by the PowerPoint client application. These .eot files can be extracted from the ".pptx" file and used directly on web pages.