In budding yeast, the DNA-binding protein Rap1p orchestrates a negative feedback on regulation of telomere length and the organization of a heterochromatin-like telomeric compartment. Recent studies have led to the identification of functionally related telomeric proteins from fission yeast and mammals. These advances underline the key role played by the proteins that bind to the duplex part of telomeric DNA and reveal an important structural diversity among telomeric proteins.