Like OTF fonts, EOT supports both Postscript and TrueType outlines for the glyphs.
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."
WEFT is used by webmasters to create 'font objects' that are linked to their web pages so that users using Microsoft's Internet Explorer web browser will see the pages displayed in the font style contained within the font object.
Critical security update for Windows Vista KB969947 resolves several security issues that "could allow remote code execution if a user viewed content rendered in a specially crafted Embedded OpenType (EOT) font".
Such fonts could be embedded in Web sites, including those that host user-provided content.