I would humbly like to offer another alternative. By no means I want to imply it is any better than the other options of building a website with Delphi, but if you're willing to not use the RAD-side of Delphi, and its IDE, but want to use the Delphi language and its compiler, and combine HTML and server-side logic code in the same files much like (early!) PHP or Cold Fusion, I've created this solution to do just that: https://github.com/stijnsanders/xxm#xxm
What I wanted was a way to create a website by working on the code, press F5 in a browser to put it to work, but have the website itself run from a freshly compiled DLL, from a Delphi project. This same DLL would use a generic interface, so by moving it from your development machine to a online web-server, you could use the same DLL with Apache httpd, IIS, or SCGI.
It may take some work to get it going and set it up, and you don't have any support of a platform, but if you know what you're doing, that can be a good thing. Most other web-platforms I've witnessed all take some freedom away by the choices that have been made in their design, and you inevitably will hit these limitations later when you're trying to do something the platform wouldn't support.
If you're interested to see a fully developed web-application on xxm, have a look here: https://github.com/stijnsanders/tx#tx
(I once made "get started" tutorial, but should really update it, replace xxmLocal with xxmHttp and IE with Firefox or Chrome...)