The WFDB (Waveform Database) library supports creating, reading, and annotating digitized signals in a wide variety of formats. Input can be from local files or directly from web or FTP servers (via the W3C's libwww). WFDB applications need not be aware of the source or format of their input, since input files are located by searching a path that may include local and remote components, and all data are transparently converted on-the-fly into a common format. Although created for use with physiologic signals such as those in PhysioBank (http://www.physionet.org/physiobank/), the WFDB library supports a broad range of general-purpose signal processing applications.