One thing that I cannot understand is why a business that is not a one-man-show would use outdated software, especially something like Internet Explorer 6 or 7 or anything under 10.
I can understand if a very small business of private person who do not have an IT department of IT support can still be stuck with such old software, but a big business with branches all over the country should know that especially IE < 10 has security risks and do not support HTML5.
So if you then ask a supplier to write you a web application and the web application makes use of HTML5, then you should not wonder why it does not work with your IE 8 browser.
I can understand that it might not always be possible to upgrade all workstations to the latest operating system if you use expensive proprietary operating systems, but then you can at least standardise on an open source browser like Firefox or a free browser like Chrome. Both of them have very good track records for security and they support HTML5 and keeping them up to date does not cost anything.
So why are your staff stuck with an old, insecure browser that does not support HTML5? We are not living the the 90's anymore!
The same goes for office suites. LibreOffice is kept up to date and there are other alternatives like OpenOffice (Backed by Apache, Oracle and IBM). With a little training, you can move all your users over to LibreOffice or OpenOffice and never have to pay for an upgrade again and always have the latest stable and secure version of the software available, no matter what OS you run.
To me it just makes sense to invest some time and money once to get ensure a future of not being locked in. In the long run it saves money and if enough businesses does that, it might even force Microsoft to come to the Open Document Standards table and bring the price of it's Office suite down or even make it also free, which will benefit everybody as we will have a real open document format that everybody can use and nobody can be locked in.
Just my humble opinion.