Rick Maschek successfully conducted a static test of the small test motor which used a finocyl core geometry for the SStS project. This is exciting because of the possibilities that complex core geometries open up. Many of the most impressive small sounding rockets utilize a monolithic grain segment with a complex core geometry. Arguably on of the earliest and most successful is the Loki dart which could deliver a small payload to 34 miles despite being only three inches in diameter. It used a simpler cruciform core design.
Photos and video courtesy of Rick Maschek.