Jon Udell: If we recapitulate the RSS/Atom experience with ICS, and lots more ad-hoc ICS feeds arrive on the scene, charts like this will go even redder. To make them go green, we’ll need a more robust ICS validator.
Jon has done an excellent first step: demonstrating that there is a problem.
The next step is harder, and for the feed validator was borne mostly by Mark. For each of the red entries on that page, somebody needs to identify what should be tested for, and for each test identify a short message, an explanation, and a solution. Identifying real issues that prevent real feeds from being consumed by real consumers and describing the issue in terms that makes sense to the producer is what most would call value.
Once this is done, the coding is straightforward. I’d be willing to volunteer to take on a large chunk of this.