The Landolt-Börnstein subvolumes III/44A and III/44B update the existing 8 volumes III/41 about Semiconductors and contain new Data and Updates for I-VII, III-V, III-VI, IV, VI and II-VI Compounds. The text, tables figures and references are provided in self-contained document files, each one dedicated to a substance and property. The first subvolume III/44A contains a "Systematics of Semiconductor Properties", which should help the non-specialist user to understand the meaning of the material parameters. Hyperlinked lists of substances and properties lead directly to the documents and make the electronic version an easy-to-use source of semiconductor data. In the new updates III/44A and III/44B, links to existing material in III/41 or to related documents for a specific substance are also included.