h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I don't know whether it is worth noting that in UK it is a legal requirement, under the DDA (Disability Discrimination Act), for websites that provide information or services to the public to be accessible. Similar requirements are expected soon European legislation.

Also, it takes more than accessible web design to make good web design. It is perfectly possible to have a website that is 'accessible', but completely unusable.

There are a number of other helpful resources for those interested in accessibility and accessible web design. Try these for information that is slightly more readable than the W3C technical documents:
http://www.accessify.com/tools-and-wizards/
http://www.rnib.org.uk/accessibility/
http://www.webable.com
http://www.accessiblenet.org

I have not had a chance to look yet, but do you know if any of them have a tool that scales slightly less dreadfully than the RNIB's bobby tool?

It is a wonderful tool if you only have a couple of pages on your website, and you don't change them often, but I have republished something like 150 pages in the last five months, which makes it completely unusable.

What is needed it a tool you can download and use offline, similar in principle to htmltidy.

Not quite sure what you are after. Bobby has nothing to do with the RNIB - it was originally a free product (from Center for Applied Special Technology) that was downloadable and usable offline, it was never particularly usable. Then it was bought out by the company Watchfire (link in the original article). It is still available as an offline product, but now costs rather a lot

Other free, open source, ones are in development Waizilla, for example (see http://www.waizilla.com ), but nowhere near ready.

However, automated tools are only of very limited use in accessibility testing really and over reliance on them could even be dangerous. For instance, they can tell you whether images have alt text, but not report on its appropriateness; nor can they check on colour contrast or check whether pages work without stylesheets. In the end manual checking is always required.

Some of the tools to check the 'accessibility' of websites ain't too good though: I remember someone a while ago had run the H2G2 stuff on teh BBCI site through one such thing, and it said it was inaccessible... Well I'm using it fine with screenreader (JAWS) As to the DDA and the legal requirement, I don't think this is being enforced much yet, as far as I know I still can't use the Sainsburrys homeshopping website, because of accessibility issues with the checkout process....

I now what you mean about sainsburry's.

however a lot of the problems with such sites are nothing to do with their actual usability, and a lot to do with presentation.

I know of some sites that you can view perfectly well with mozilla when it is reporting that it is internet explorer, but who fail misserably when you don't set it to report that, even though it still executes the same code in the browser.

basically, their server checks to see if it is one of the browsers known to work with it, and does something strange if it isn't.

This may or may not be the case with their website.

another equally stupid move is using browser specific commercial plugins to do generic tasks, meaning that only those using those specific browsers can use those features.

this is a mistake the tax office have made.

Yes, as I said before automated tools are not all they're cracked up to be - they produce too many false positives (sites that are nor particularly accessible passing the tests) and possible failures (sites that have reasonable accessibility getting picked up on a large number of insignificant possible faults that need checking) to be of much use.

I must also be said that JAWS is a very sophistocated and expensive screen-reader so can cope with a number of 'inaccessibilities' that other screen-readers may not be able to.

Sainsbury's is better than it was when first launched - it had loads of Java applets, which were very clunky and broke just about every accessibility guideline. Tesco on the other hand have a special accessible version of their site - although segregating audiences with different version is not the best practice way of doing things.

The only truely accessible grocery shopping site I've found in the UK is the Waitrose site, it is just very well designed, I must check the sainsburrys site again, see if they've sorted out the check-out issue (I heard they were working on this)... The tesco Accessible site is alright* but lacks features of sites like Waitrose, and doesn't carry the full range of tesco's products... equality... JAWS is quite expensive, think its still just under £700, possibly more, I forget... It is a truely useless application when it comes to working and interacting with other things you might percievibably run on a PC, it regularly crashes this machine four or five times a day, gives an error message from IE on just about every time I exit it.... If JAWS was a £30 PC game, they'd be releasing point releases/upgrades freely and constantly over the net, but, with JAWS they don't ever seem to do this... I can't imagine how badly JAWS will cope with XP; as far as I know it is still effectivly a DOS piece of software, thats just been 'fiddled' with to run in win95/98 etc., wish they'd get their act together and recode JAWS, its more than overdue...

Both Sainsburrys and Tescos are now accessible; Tesco's did away with their having a seperate 'accessible' site some years ago, in favour of making their main site betterer Flash and javascript still seem to cause the most accessibility problems Though as an accessibility tester these days they do help provide me with quite a lto of testing work
There still doesn't seem to be much to replace manual testing of pages, a lot of the automatic checking tools don't even seem to have been updated as yet to WCAG 2.0...