ScoreDoom 2.8 and it's Add-On Pack have been released and it will give all those iwads and pwads in your collection more longevity.
ScoreDoom features include:
*Fun Scoring system added to Doom
*Local Hi Scores and Online Leaderboards.
*Co-op scoring ala Halo3's campaign 'meta-game'
*Add-On Pack has over 250 new doom-like monster and over 15 new doom-like powerups, and a fun 'Boss-Rush' mode.
More information and download @ Scoredoom.com