The DVD episodes end with Joss Whedon and Tim Minear's Executive Producer credit washing across the screen, left to right. On the television episodes, instead of their names, a wireframe model of Serenity fades up.
The two-hour pilot "Serenity" also featured a scene in Simon's cabin with him and Zoe: he's listening to an encyclopedia entry on the Battle of Serenity Valley, from which the ship gets its name, and she comes in and gives an eyewitness account of it, from Mal commanding over 2000 people after a week due to high officer casualties, to both sides stacking corpses for cover, to medical relief for both sides being held back for a week after a cease-fire was declared, to her and Mal being the only survivors of their platoon, and that she'd kill Simon on a word from Mal.
The first few episodes aired on TV featured the opening credits as they appear on the DVD Boxed-Set. However, the network feared the audience wouldn't understand the show's rather complex cast of characters, so asked that a different opening, complete with voiceover, be used for episodes airing later. The Region 1 DVDs are missing the voice-over introductions that were present when the later episodes aired on television, showing only the original credits, as intended by the producers.