An easier approach would be to use DlhSoft Gantt Chart Web Library which includes the client side components encapsulated by ASP .NET Web controls, supporting both initialization and post back data change handling for you. This is great if you are a SharePoint® 2010 developer. But as the included ASP .NET components require .NET 4, while SharePoint® 2007 supports .NET 3.5 only, and even older SharePoint® 2003 was originally built on .NET 2.0, what do you need to do in these cases?
Until today there was no middle solution. But we have managed to prepare a small and easy to install Gantt Chart Web Library rebuild pack for .NET 2.0 (and .NET 3.5) for this purpose. Although it doesn’t include the advanced features of the components, but only a basic subset, loading and presenting Gantt Chart data and getting changes back to the server is kept at the same level of easiness as in our standard ASP .NET 4 build. Therefore, if you’re a SharePoint® developer that requires previous .NET platform versions due to legacy system constraints, this is exactly what you need. Enjoy!