And that's the problem with that list there is a load of stuff listed that isn't really D20 Modern, and much of that is the hardcopy published stuff.
For example the Crime Scene series by Hogshead isn't D20 Modern, its D20 in a modern setting but it doesn't build on D20 Modern's skill set it instead introduces its own, it doesn't use D20 Modern's base classes and instead introduces its own class system. So that's 4 supposed D20 Modern products that arn't actually readly useable without some conversion work.
The Horizon series is the same (That's minus another 3). X-Crawl, Real Life Roleplay, etc. etc. Most of these don't require D20 Modern and use none of its rules, in fact adapting them to D20 Modern would involve a lot of work. When you strip away all of that there isn't actually anywhere near as many products as your list makes out.
Most of what's on that list isn't immediately of use to someone using D20 Modern without some major alterations. It would be handy if you list actually listed what used the D20 Modern rules, and not there own version of the D20, or at least had a tick box to that effect.