Tim Hardwick at MacRumors is reporting that IKEA's Trådfri smart lighting system now support Apple's HomeKit.
The lights require a Ethernet-based gateway, not unlike the Philips Hue bridge, although Hardwick also reports that the Trådfri bulbs can work with a Hue bridge.
The bulbs run anywhere from $12 to $18 a pop, which is roughly what Philip's dimmable LED bulbs cost.
Update: Turns out, MacRumors was incorrect. IKEA says support is coming this fall.