The central aim of Cufón is to become the successor to sIFR, which as we have seen, is very difficult to set up. It consists of two parts, an online font generator (essentially a front-end to FontForge) and a JavaScript rendering engine which is uploaded to the target site. The font generator allows the user to upload the chosen font (EULA permitting), where it is converted firstly to an SVG (Scalable Vector Graphic) file, then to VML (Vector Markup Language) and finally to JSON (JavaScript Object Notation). SVG is not retained in the generated file due to speed issues. Because the file is essentially JavaScript no plug-in is required for viewing the converted text.

>This text is set in OldStyle using Cufon.

In practice Cufón is very easy to set up and use. The font generator interface allows the user to upload normal, bold, italic and bold italic fonts and group them under a user-specified font family name. The user then selects which glyphs are required from a checkbox list. Latin is checked by default and would be sufficient for most users, unless specialised characters are required. The user can select all glyphs but this is not recommended as the resulting file will be unnecessarily large. The interface also allows restricting the usage to specific domains, which is a requirement of some typefaces EULA. Finally, the user can include or exclude kerning tables. The inclusion of these tables slightly increases the file size of the generated font but is highly recommended for improved type performance.

Technologies such as this encourage the use of typefaces other than the standard set we’re all used to (Arial, Georgia, etc.).
― cameron moll

Implementing Cufón is as simple as linking to two provided JavaScript files, the former being the rendering engine, and the latter the font itself. A snippet of JavaScript is then pasted into the head of the page which specifies which html elements should be replaced. Cufón replaced elements can be styled like any other html element using CSS, eg: font-size, color, etc. Font weights and italics may only be used if the corresponding fonts were included in the upload to the font generator.
The example above took no longer than five minutes to set up, from uploading OldStyle to its inclusion on this page.

In summary

Cufón is currently supported by IE 6/7/8/9, Firefox 1.5+, Safari 3+, Opera 9.5+, and Google Chrome. It loads quickly as it is entirely JavaScript, particularly when compressed. While it can be used for larger bodies of text, it has a significant drawback in that Cufón text cannot be selected. The recommendation therefore, is to limit its use to headings/sub-headings and navigation elements.

Legal Note: The use of Cufón requires an extended or separate license from some Type Foundries, eg: Berthold, FontFont, FontSmith, Hoefler & Frere-Jones, ITC and Linotype. Adobe fonts are known to be safe for use.
Foundries are understandably cautious of licensing for Cufón as the possibility exists that the Cufón code could be reverse engineered to reproduce the original font file. Check your chosen font's EULA before using the Cufón generator.