Just had a flyer from Heinemann - a little quote to make you laugh. I see what they were thinking, but even so...
Because IIS is a standard part of most Windows server packages, we've concluded that this is the best web server to use.
Other web servers, such as Apache, often require licensing so wouldn't suit as many schools.
Fair play to them for releasing their titles as 'intranet-based applications'. Makes deploying them a cinch, but the ones I've had so far are coded in asp, so even if you wanted to 'license' an Apache server to run them: tough! Unless someone has developed an open-source compatible? Geoff? ;)