… The term “independent film” is essentially impossible to define in this kind of situation. Does it refer to any non-traditional studio film? If so, “The Lord of the Rings,” “Twilight” and “Chicago” would all be near the top of this chart and arguing any constitute the definition of “independent film” is quite challenging. The lines between studio and indie began to blur in the 1990s, when through mergers and/or acquisitions, indie institutions like Miramax and New Line started to look more and more like studios. In the 2000s, if one were to include either distributor in a list of the top grossing “indies,” they would dominate 15 of the titles – few of them “indie-like.”
So, for the purposes of arguable fairness, unless a studio or “mini-studios” like Miramax, New Line, Lionsgate, and recent Summit Entertainment acquired a truly independent production (like Paramount did with noted “Paranormal Activity,” for example), it will not be included on this list. What will be included, again in arguable fairness, are studio specialty divisions. Fox Searchlight, Focus Features, Sony Pictures Classics, and now defunct Paramount Vantage and Warner Independent Films, have released some of the most notable independent films of the decade, even if they are associated with studios. …
https://www.indiewire.com/article/b.o._of_the_00s_the_top_grossing_independent_films_of_the_2000s/