There's no denying that Fringe has a lot in common with The X-Files. In fact, they probably exist in the same fictional universe (see Fringe 2x01, where the subcommittee tells Broyles "...the old 'X' designation and your Fringe investigations have been indulgences in the federal budget for over half a century").
The visual references to XF are obvious. I'm a huge fan of both shows, so I re-cut the X-Files opening credits using only clips from Fringe.
The truth is out there: there's more than one of everything.