Antibody engineering has been an extremely intensive research area for many years. Recent achievements discussed in this review include: (i) significant improvements in the field of selection of antigen-specific antibody fragments on bacteriophages; (ii) new structural work, in particular using NMR; (iii) the cloning of essentially the complete set of human VH genes; (iv) the use of antibodies to catalyze complicated chemical reactions; and (v) novel antibody fusion proteins to potentiate immune therapy. An interesting new development is the replacement of antibodies with more stable protein scaffolds for many future biotechnological applications.