This is absolutely true, but in most cases the platform or type of engine (and for that matter the protocol, the data file format are too) are completely transparent to the application. In fact there is a large realty company in Dallas TX that is running Great Plains software against a Pervasive.SQL 2000 Linux server at several sites and loving it. As you can imagine, GP would not like that at all, especially since they have been purchased by MS ;-) So the moral is if you want support from your application vendor make sure that they support Linux, but if the app is custom, old, or unsupported, or you just don't care if the app vendor provides support for the type of database server engine used then Linux should work fine. I would certainly download the eval and test it first before purchasing it, but in more than 99 of 100 cases this is true that you can switch out servers from NT to NW to Linux and vice versa and it all will work.
Pervasivite