This is Super Flight Planner 4 for FS2004 and FS/X Release Candidate 5 (version 4.0.0.690), free for all to download and test. Note that starting this release, Win9.x, WinME and NT4 are no longer supported. You must be running Windows 2000 or higher to run Super Flight Planner

Note, I also uploaded this release on avsim.com, if you have troubles downloading from here.