Back then, I wrote the mobile web applications in c++ and used ISAPI. This was complicated as I had to render the information in WML or HTML depending on the phone browser capabilities. My latest incarnation at MobileQuery.com is built using c#/ASP .NET which actually calls my older ISAPI code for some queries. The ASP.NET mobile controls now take care of the rendering for me – although it is less efficient than my previous home brew solution.
Some queries access local data (files) while others access other servers for data. New queries are defined in a SQL Server database rather than in code so it’s fairly quick and easy for me to set up new ones.
I am not a great fan of web portals. Most force people to view too much stuff they don’t really want to see. Personally, I cherry pick my own and third party services I want to use and aggregate them in the (smartphone) browser. This is the thinking behind these single page mobile applications.