Wikipedia;
The ARJ21 will be built using tooling which was originally provided by the McDonnell Douglas company for licence production of the MD-90 in China. Because of this, it bears a strong resemblance to the DC-9 series of aircraft, with an identical cabin cross section, nose profile and tail. An all new supercritical wing has been designed by Antonov.[5] It will have a sweepback of 25°, and be fitted with winglets to improve aerodynamic performance.