The Pixif
A PIC is used as a SPI Master to create a simple interface to up to 21845 NeoPixels. After being configured with the number of attached NeoPixels the Pixif continuously retrieves the RGB values via SPI and generates the NeoPixel GRB bitstream. The update rate may be throttled via a synchronization input. This approach frees the host processor to concentrate on its algorithms especially when its SPI Slave has DMA support.
The PICsellator
One PIC, some NeoPixels, a little math, and a big bucket of randomness.
Madison's NeoClock - A PIC + KiCAD + NeoPixel adventure
This is a desk clock based on the NeoPixel ring-12 and -24. It displays hours, minutes, and seconds in a unique way using time-dependent colors and tapering. The clock adjusts its brightness according to ambient light and has a ChronoDot to keep extremely accurate time.