There is a loose link in the Pearl.
But other than that it's pretty much it's own thing. Chronologically it indeed is way before the movie, in the stock game that is.
With the mod the date is moved closer to the movie (Probably for historical accuracy reasons?), and there are some other tie-ins.
Back to the stock game.
In the Russian version (v1.0.3) there is a scrapped quest in the files that features Jack:
ORIGINAL Akella Post-Ending Jack Sparrow Sidequest + Russian Patch Files
So perhaps there would have been a closer link between them.
But other than that it's pretty much it's own thing. Chronologically it indeed is way before the movie, in the stock game that is.
With the mod the date is moved closer to the movie (Probably for historical accuracy reasons?), and there are some other tie-ins.
Back to the stock game.
In the Russian version (v1.0.3) there is a scrapped quest in the files that features Jack:
ORIGINAL Akella Post-Ending Jack Sparrow Sidequest + Russian Patch Files
So perhaps there would have been a closer link between them.