RNA shows significantly higher folding dynamics than DNA because it predominantly occurs in its single-stranded form. Depending on sequence, length, and possible interaction partners, a single RNA strand can adopt a variety of folds, leading to a broad spectrum of distinct conformations with characteristic functions. Due to its folding versatility, RNA has the potential to perform a wide variety of functions, including regulation of gene expression and catalysis. Throughout evolution, numerous functional RNAs have emerged, and this process continues today. It is accompanied by significant efforts in in vitro RNA engineering, adding an “artificial evolutionary” aspect. In this chapter, we describe how different functionalities have been engineered into a small self-cleaving RNA. We demonstrate the power of this RNA in supporting highly dynamic processes, such as RNA recombination and splicing. These processes require cascades of conformational changes, and RNA folds to perform individual processing steps and to generate functional novelty without sequence change.