Specifically, work on FreedomHTML is being initiated in response to W3C's plan to recommend “Encrypted Media Extensions” (EME) in the context of HTML5. Such hooks for DRM (Digital Restrictions Management) are incompatible with fundamental freedom principles.
Since FreedomHTML is a profile and not a fork of the HTML specification, there is no risk of interoperability problems that could otherwise easily arise from the kind of thing being specified differently in different variants of the HTML specification: A profile is a kind of meta-specification: The profile specifies a subset of the features of the underlying specification. The FreedomHTML profile will recommend a very large subset of HTML, namely the subset that contains all the good features, just not the bad stuff like hooks for DRM.
Specifying this large subset of HTML precisely has many benefits. For example, organizations can make it part of their website policy that all webpages must conform to FreedomHTML. When procuring website development services, they can simply tell the web developer that all webpages must conform to a specific version of the FreedomHTML specification, and everyone is able to use the specification document to determine exactly and precisely what that means.
Automated HTML validation tools can be easily modified to check FreedomHTML conformance.
It is expected that some browsers will support FreedomHTML by warning Internet users before displaying a webpage does not conform to FreedomHTML.
Work on FreedomHTML is just starting.