Dimmable compact fluorescents are available, they are usually made with “cold cathode” technology. You can find dimmable bulbs here on Amazon. There’s a 12 pack available here, and a dimmable compact fluorescent spotlight here. 1000 Bulbs also sells a wide range of dimmable compact fluorescent bulbs
A 15W dimmable floodlight compact fluorescent. Works with standard dimmers. Available from: Amazon for about $15.