The IKEA kitchen cabinet system is genius. IKEA cabinet design is not. People want to use the IKEA system, but dread having a kitchen that looks like an IKEA catalog.
Kokeena is a marketplace that brings together door makers and DIYers and makes it easy sell and buy doors specifically made to work with IKEA cabinets. It's Etsy for IKEA cabinets.
DIYers gain access to custom doors usually only available "to the trade." Door makers gain access to the lucrative DIY market.