I need to insert a horizontal bar chart in a web page. The thing I have to do is very similar to a Gantt Chart.
I could evaluate also a server generation of the graph. In case my server side language is Python.
It will be part of an internal project with no internet access, so Google Charts isn't an option.
Have a look at the flot jQuery plugin:
The library can produce bar graphs, and is used by our host site - have a look at Stack Overflow Reputation History page.