I'm not big on their history either, but basically XWF was Hulk Hogan and Jimmy Hart's attempt to fill the void left by WCW's demise. I believe they had some financial backing, and were trying to get a TV deal. XWF had a lot of former WCW guys, and was trying to be a "family friendly alternative". They taped their episodes at Universal Studios in Florida. Their big problem was that they were unable to secure a TV deal, and WWF ended up signing Hogan, Piper, Hennig, Lawler and Sable (who was their "commisioner") to deals.
WWE has the rights to their footage now, obviously.