Voici la chronologie de DNF
Janurary 1997: Work on DNF started.*
April 1997: Quake 2 engine purchase announced. (they got it in mid-late 1997 before Quake 2 was released). Scott Miller states that he is confident that DNF will be released by mid 1998 and prey in late 1998 making 1998 a bit year for 3DR. He also mentions that his confidence is not misplaced.
August and September 1997: First screenshots in PC gamer (hummer, farmer i think).
May 1998: First DNF E3 video shown. You can see that a lot of work has been done.
Late 1998: 3DR announces switch to Unreal tech. It is expected to take no longer than 6 weeks and 3DRealms says "DNF is a 1999 game."
Mid 1999: 3DR admits that the engine switch took a lot more time than originally estimated.
Late 1999: 3DR announces upgrade to UT level tech. It is expected to take two weeks. 3DR releases a Christmas card saying that DNF will be released in 2000.
2000: I don't think anything happened. They released some sexy screenshots in late 1999/early 2000 (for the time). Broussard begins claiming that DNF development did not start until 1998. Inquiring minds wonder how they got so much done before May (E3) 1998.
May 2001: 3DR comes out of nowhere and puts DNF up at E3. They state that DNF will be released in 2001 and the end of the E3 2001 video says "WID in 2001". Many part of the video bear a clear resemblence to the 1999 screenshots.
October 2001: Broussard posts "sorry guys, it won't be a 2001 release" on the VE3D forums. "Don't worry, the last major hurdle is AI."
Unknown 2001: Broussard states that DNF will definitely be out before Unreal 2.
January 2002: Voodoo Extreme makes a list of top 10 titles to be released in 2002. #1 on that list is Duke Nukem Forever. Someone posts "when will we see something" in the 3DR forums. Broussard responds with "soon".
June 2002: The "soon" thread gets locked.
Unknown 2002: Broussard states that DNF will definitely be out before DooM 3.
2003: Broussard states that DNF has been "on track since early 2002" and that they haven't reached the light at the end of the tunnel, but "they finally found it." He wisps away the years between January 1997 and January 2002 and wishes people would consider DNF's development as if it started in 2002 (this is a strong hint that DNF was far from complete). Unreal 2 released.
Broussard adopts the "DooM 3 and HL2 will have been in development for 5 and 6 years when they're finally released -- DNF isn't taking that much longer" belief (notice: his numbers are very inaccurate).
Late 2003/early 2004: Take 2 complains about DNF development and expects it around "late 2005". "At this point we're just hoping the team [in garland] will finish the project."
2004: Broussard states that DNF development has been on track since "late 2002/early 2003", bumping up his earlier statement in an attempt to fight back release expectations. It is clear, from this behavior, that DNF will not be released this year or next. DooM 3 is released. Half Life 2's release is anticipated this year.
So the most reasonable points in which they could've completely restarted would've been after each of the E3 videos. They could've restarted after the E3 1998 video or after the E3 2001 video. Luckily, you can refute both of these possibilities by simply looking at what Broussard was saying back then -- the Unreal engine upgrade was certainly not expected to require them redoing much. Things were added and tech was changed, things were adopted. This was all stated in interviews with Broussard himself.
It is more difficult to question whether they've restarted at some point after E3 2001. Clearly, in late 2001/early 2002 when Broussard was saying that the last major hurdle was AI and "soon", he could not have just restarted the project. Furthermore, in 2003 he stated that development had been good since early 2002. If this was the case, then there was no point at which he could've restarted (unless you restart while telling fans "the last major hurdle is AI" and "soon").
* "We've actually been working on the game since January." -- Scott Miller, 1997.
