Why do DVI drivers sometimes pause to generate fonts?
Modern fonts are defined in specialized command languages and/or programming languages that describe character shapes with outlines or, for METAFONT, paths of shaped pens. Ultimately, these complex descriptions must be converted to a rectangular grid of black-and-white dots. PostScript printers can do this conversion internally, so most users are unaware of it. However, when you use a DVI driver, such as dvialw, dvidot, dvips, or xdvi, to convert a DVI file to the format needed for a particular device, conversion to a bitmap font description is needed. The DVI drivers cache the results of this conversion, so it is normally done only once. However, the caches are machine-specific, and may get overwritten by nightly jobs that update client workstation filesystems from master filesystems, so you may see bitmap-font generation daily on your workstation.
