You probably won't have to check your site with all of the available evaluation tools out there, but it is a good idea to do so for the most common web browsers. Just as accessibility software makes it easier for people with disabilities to navigate the Internet, these tools make it easier for developers to ensure accessibility from the start. When you think you've mastered it, go back through the Section 508 compliance checklist to ensure you've met every goal.
Penn in particular nearly made the cut because I really like their keyboard accessibility. It amazes me how few sites provide visible indication of keyboard focus, when it's incredibly simple to achieve (just add a style for a:focus in your style sheet). Penn did this, and consequently it's very easy for sighted keyboard users to keep track of their position as they tab through the page. They also included a keyboard-accessible dropdown menu. However, there are some dynamic features on the Penn home page that really need ARIA markup for full accessibility. They also have a few contrast problems, most notably their slideshow navigation, which is red-on-red:
The situation has now emboldened many people. She is dealing with tons of demand letters going out across the country. Businesses have been caught off guard because they thought they had time to deal with this and become compliant, and now the Justice Dept. basically says they have to be compliant now. As soon as they deal with one plaintiff, another comes along.
Accessible Poetry adds a floating button that, when clicked, exposes a toolbar to allow for font and contrast changes. You can also zoom in and out of the page, along with mark links and disable onscreen flashes. But the star of the show is its ALT Platform area inside the WordPress Dashboard. This screen will list any images uploaded to your site that don’t have an ALT tag assigned. Even better, you can set a tag for each image directly from this listing.

The ADA itself holds different organizations to more/less stringent standards based on a host of factors, government funding being a major one. Government agencies themselves are usually held to the most severe standards. That said, while ADA has adopted WCAG as the defacto standard, from what I’ve seen it appears they’re going with AA compliance as the most reliable one. That said, we’ve done work with some organizations who’ve chosen to comply with AAA in an effort to be as buttoned up as possible from an accessibility and experiential perspective. We’ve also worked with some who have tighter budgers and aim for level A compliance and have a more “react and repair” mindset when they discover anything in their site that is giving someone hardship from an accessibilirt standpoint.
UPDATE: Since writing this post in August 2017, several important changes have taken place in the laws regarding ADA compliance for websites. On December 26, 2017, the Department of Justice announced that they have withdrawn the Obama-era Advance Notice of Proposed Rulemaking mentioned in this article which intended to require ADA website compliance. The DOJ’s withdrawal announcement stated, “The Department will continue to assess whether specific technical standards are necessary and appropriate to assist covered entities with complying with the ADA.”
When choosing an aid or service, title II entities are required to give primary consideration to the choice of aid or service requested by the person who has a communication disability. The state or local government must honor the person’s choice, unless it can demonstrate that another equally effective means of communication is available, or that the use of the means chosen would result in a fundamental alteration or in an undue burden (see limitations below). If the choice expressed by the person with a disability would result in an undue burden or a fundamental alteration, the public entity still has an obligation to provide an alternative aid or service that provides effective communication if one is available.
Hi Ashley, Thanks for the feedback. However, I respectfully disagree about JAWS. There was a time many years and versions ago when screen readers didn't support id attributes as targets, but that's no longer true. I just tested my site with JAWS 14 in both IE9 and Firefox 17. In both browsers JAWS identifies the link as "Same page link Skip to main content", then if I click on that link using the left mouse button I jump directly to the "main region", and a couple of down arrows later I'm on the main heading. I actually wrote an earlier blog post about this very topic.
The Americans with Disabilities Act (ADA) was first passed in 1990. Twenty years later, the US Department of Justice released an update called the 2010 ADA Standards for Accessible Design. These standards cover the design of physical spaces and have been interpreted to include web locations as well, so it can be difficult for the would-be accessible website designer to use them.