Silicon-based low-dimensional nanomaterials and nanodevices are reviewed with emphasis on building the materials base for a wide variety of nanostructures that are potentially useful in future nanotechnological applications. Specific topics covered include the similarities and differences of silicon and carbon, category of nanomaterials, synthesis of silicon nanowires and silicon nanodots, etching of silicon nanowires, silicon nanowires as platforms and templates, silicon-based low-dimensional nanomaterials, techniques for nanomachining, nanomanipulating and nanoassembling, quantum-size effects, fabrication of nanodevices, atomic- and molecular-scale technologies, and interconnection and integration.