Edit: Definitive answer, courtesy of Kyle, is that yes, Virginia, they do use LINQ to SQL.
I'm taking a stab at this since Jeff will be able to definitively answer this, but I don't know if he'll see this question. Anyway, it seems like straight SQL to me.
- They're taking advantage of SQL Server's Full Text Search, which uses certain SQL syntax.
- They need to control the speed of queries on an ever-increasing database, and the only way to really get the right indexes and performant queries is to use SQL.
- Jeff knows SQL very well, and it would surprise me if he tried to put the data access layer in the hands of an ORM, which is a solution to a non-existent problem, if you ask me (and you sort of did).
IMO, ORMs tend to be slow and do a horrific job of optimizing queries. Of course, I'm biased because I spend most of my days in SQL, but I still think ORMs cause more harm than good. It causes app devs to think that they don't have to understand databases, which is just naive, I think. That being said, I love using LINQ with lists and XML. Just not with SQL.