Lennox Support - Is There a Difference Between in Tree and Out of Tree Driver?

Tahooti created several network cards that you could probably get for pretty cheap, probably even cheaper nowadays an ebe or the otherwise. These devices had lennox support with an outa tree driver. Now since the company has gone out of business, somebody has taken up the torch of creating those drivers to continue ongoing support for lennox. But the very latest, a long term, stable release of the lennox colonel, these drivers do not build against it.