This web site
This web site is serving Microsoft Active Server pages.
The pages here are created using 100% Microsoft notepad.exe. Hence there are no superfluous tags or whatever. Indents there may be, but there shouldn't even be an extra space character elsewhere. What you see is what you get.
Two typefaces are used in these documents.
The main body is Tahoma, which most web browsers should be well endowed to handle. Otherwise, the fallback is Verdana and then Helvetica and then the default sans serif typeface.
The page banner uses Georgia, which comes gratis with Windows XP and Windows 2000. Some risk is taken here. But since the intended audience for Gantt Designer is Windows users, the chances of having to fall back should be low. Fallback is to your default serif typeface.
Accessibility is a consideration. No font sizes are hard-coded, and most links can be fast-keyed.
This product
Gantt Designer is developed using C# in Visual Studio .NET 2003 and .NET Framework 1.1. No, notepad.exe is not the main tool as we rely heavily on Intellisense.
The .NET Base Class Library, especially GDI+, is used extensively and everything else is written. It is pure .NET. The Interop namespaces are not touched. There are no third party components.
Testing so far has been on .NET Framework 1.1 only. According to Microsoft documentation, it should run fine in .NET Framework 2.0.