San Fran, CA Random SW fact...

Matty, The Delta 7 aka Jedi Starfighters and it's future derivatives (the Eta-2 "Jedi Interceptors") were created by Kuat Engineering Corps. aka Kuat Drive Yards. The same corporation that created Imperial Star Deuces (Star Destroyers for the pilot slang impaired) and the KDY 150-v planet-defender class Ion Cannon used on Hoth. During the evolution of the TIE fighter series Sienar Fleet Systems used Kuat's designs as the basis for the TIE Fighter due to the success of Jedi pilots had with the Delta 7 series in combat. Effectively using lightly armored unsheilded but incredibly agile ships with decent firepower.

Sienar got the sole monolpoly to produce the Empire's fighters (aka TIE class starfighter) rather than the ARC series of fighters developed by Incom (who later make the Incom T-65B aka X-wing) which were more costly but better armed and defended to protect their pilots better in engagements. However, this decision to soley use the TIE series later came with a huge flaw and cost the Empire the war over all. TIE Pilots aren't Jedi, they do not have the ability to use the Force in conjunction with the fighter piloting ability in a battle scenario. Thus TIE pilots don't survive past their first tour of duty unless you're totally bad@ss like Baron Soontir Fel of the Imperial 181st TIE Interceptor group. Regardless, due to the very low survival rates of TIE pilots it's rare they grow into veteran pilots and thus the lack of elite pilots was a weakness the Rebel Alliance exploited in battle. Rebel pilots who use superior starfighter that protect their pilots could grow into veteran pilots and survive battles. It made Rebel pilots even better overall and that was something the Empire failed epically to recognize. When the Empire gave Sienar Fleet complete control over production of all the starfighters created for the Imperial Navy they dissolved the Incom Coporation. The Incom design team that was developing the Incom T-65B class space superiority fighter (X-wing) defected to the Rebel Alliance bringing the design and prototypes of their newest starfighter, the X-wing, just prior to the discovery and destruction of the first Death Star.

When you asked if Sienar developed the Jedi Starfighters I really didn't think so. It makes more sense the Kuat did because of the triangular design and all (Delta 7 and Star Destroyers have similar silhouettes). The only thing I looked up was the Jedi Starfighter manufacturer. Everything else was ALL me.

Now you know, and knowing is half the battle.