I found this in a WIRED review of the book, "Warbirds: The Story So Far"
"Territorial scuffles that arose between WarBirds' original creators and the company that bought out the game, iEntertainment, were the cause of an angry walkout earlier this year.
"[Game creator] John MacQueen walked out of a meeting with the vice president of iEN and announced to his staff that he was leaving the company," Williams said. "Every single person picked up and followed him to his new company."
WarBirds' original creators, John "Killer" MacQueen, Dale "HiTech" Addink, and Robert "GunJam" Salinas have since formed their own companies. Within the Warbirds community, people feel that groups will split off and coalesce around the new sims that emerge from these companies."
HiTech went on to create Aces High, and I think WWII Online was another spinoff startup from WarBirds, but I don't know if it was Killer or Gunjam, or both.
My own involvement dates back to WarBirds in late '98. I was home from work recovering from pneumonia, and out of boredom I checked out a WarBirds demo CD that a woman I worked with had given me. She had been on a cruise, and had met and been chatted up by none other than Wild Bill Stealey, who gave her some demo CDs. I don't know how she knew I had an interest in WWII aviation, but once I installed WarBirds and tried it I was hooked, hard. Even though I was still sick, I went out to my local CompUSA and bought a full Thrustmaster "Top Gun" HOTAS package. I think it took me much longer to recover because I spent so much time playing and not enough sleeping. This was back when WarBirds was $2/hr for online play.
I also had played BattleHawks 1942 and SWOTL, but online play with voice comms between players changed everything for me.