>>Why then SQL Server?
>
>Because this is how the product has evolved over the years. The engine runs on .NET now for four years and on SQL Server for a while. There were too many limitations in VFP and it was time to adjust the backend as well, so to overcome a VFPOleDb provider severe bug as well. What we had in PHDBase was exceptionnal. However, to have the same from the full text indexing in SQL Server is not that obvious. For some issues, it is better. But, I lost some of the functionality we had in PHDBase. It is also known that I do not have the millions or billions that Google has to offer the same flexiblity for the search. I think for the low scale Web site the Universal Thread is that we have done pretty well so far in regards to this full text indexing.
>
>If I can find more ideas on enhancing it, I will let it know once available.

You may want to look at Lucene.NET - it's free and the search is excellent (and easy to incorporate into a .NET app).

http://incubator.apache.org/lucene.net/