Introduction.-Characterization of Hammerhead Ribozyme Reactions.-Mechanistic Analysis of the Hepatitis Delta Virus (HDV) Ribozyme: Methods for RNA Preparation, Structure Mapping, Solvent Isotope Effects, and Co-transcriptional Cleavage.-Kinetic Characterization of Hairpin Ribozyme Variants.-Characterization of RNase P RNA Activity.-Group I Intron Ribozymes.-Kinetic Characterization of Group II Intron Folding and Splicing.-Mechanism and Distribution of glmS Ribozymes.-Structure-based Search and in vitro Analysis of Self-cleaving Ribozymes.-Discovery of RNA Motifs using a Computational Pipeline that Allows Insertions in Paired Regions and Filtering of Candidate Sequences.-Crystallographic Analysis of Small Ribozymes and Riboswitches.-Functional Dynamics of RNA Ribozymes Studied by NMR Spectroscopy.-Deoxyribozyme-based, Semisynthetic Access to Stable Peptidyl-tRNAs Exemplified by tRNAVal Carrying a Macrolide Antibiotic Resistance Peptide.-Probing Functions of the Ribosomal Peptidyl Transferase Center by Nucleotide Analog Interference.-Single Molecule FRET Characterization of Large Ribozyme Folding.-Metal Ion-RNA Interactions Studied via Multinuclear NMR.-Analysis of Catalytic RNA Structure and Function by Nucleotide Analog Interference Mapping.-In Vitro Selection of Metal-Ion-Selective DNAzymes.-In vitro Selection of Allosteric Ribozymes.-Screening Effective Target Sites on mRNA: A Ribozyme Library Approach.-A Computational Approach to Predict Suitable Target Sites for Trans-acting Minimal Hammerhead Ribozymes.-Targeting mRNAs by Engineered Sequence-specific RNase P Ribozymes.-Target Induced SOFA-HDV Ribozyme.-Ribozyme-mediated Trans-insertion-splicing into Target RNAs.-Developing Fluorogenic RNA-cleaving DNAzymes for Biosensing Applications.-Development of Trainable Deoxyribozyme-based Game Playing Automaton.-Rational Design and Tuning of Ribozyme-Based Devices.-In Vivo Screening of Ligand-dependent Hammerhead Ribozymes.-Flexizymes as a tRNA Acylation Tool Facilitating Genetic Code Reprogramming.