Html is made for interface represtation. Even every one in the web industry should know a bit of html. Is it possible to make html's extension get more usage? Like writing some dynamic scripts? To Low Technical Difficulties and save the money. Just write several lines of html to replace hundreds lines of php?
The difficulty is that html is not designed for dynamic scripts coding. So introduce some new “HTML” tags. Use these tags to boost the web developing. This is new technology that called tagcgi.
There are two open source projects using tagcgi that files are purely written by HTML without any server side scripts like php,jsp….
The one is Cgiblog whih is a open source blog system that only have eighty lines of “html”. If you implement is by php. This will cost thousands of lines. cgiblog even can faster than fastcgi c++ in server side benifit from the framework of tagcgi.
The other is rtupdate that is a open source forum which can update by real time(auto refreshing content)
This is the performance comparsion between php and tagcgi according to wordpress,typecho,lighttpd fastcgi c++ and tagcgi.

reference from http://www.cgiblog.com