After leaving much of the matter of creating a new version of HTML to Apple, Google, Opera, and Mozilla, Microsoft has begun sinking its teeth into the Web standard.

The move adds clout to the effort to renovate HyperText Markup Language, the standard used to describe Web pages, which last was formally updated in 1999. In a mailing list posting on Friday, the software giant offered a host of questions and concerns with the present proposal.

"As part of our planning for future work, the IE t...