What began as a series of small concerts at local cultural centers has evolved into a joyful gathering of tribes. Nowhere is the Bay Area's much-touted diversity more readily apparent than here; on any given bill over three weekends, viewers are likely to find hip-switching Tahitian dancing, hardy Appalachian clogging, or the precise gestures of Indian kathak. Equal parts world tour, fashion show, musical feast, and anthropology crash course, the festival is remarkable on several fronts: In this vivid swirl of embroidered skirts and flying banners, viewers begin to see the connections among countries, in how we use movement and music to flirt, fight, or simply show off. And despite the international traditions represented here, all the groups are based in Northern California. This year the festival bypasses its usual audition process and celebrates its 25th anniversary with a curated program spanning Ireland to Africa. It'll make you even more glad that you left Eau Claire.