  Starbursts are important because they can serve as local analogs of the
processes that were important in the origin and early evolution of galaxies and
in the heating and chemical enrichment of the inter-galactic medium. They may
also play an important role in the AGN phenomenon. In this contribution I
review the use of UV spectroscopic diagnostics that can be `calibrated' at
low-redshift and then applied at high redshift. From the analysis of the UV
properties of local starbursts we have learned: 1) dust dramatically affects
our view of high-mass star-formation 2) more metal-rich starbursts are redder
and more heavily extincted in the UV, more luminous, have stronger vacuum- UV
absorption-lines, and occur in more massive and optically-brighter host
galaxies 3) the strong interstellar absorption-lines directly reflect the
hydrodynamical consequences of the starburst. These results suggest that the
high-redshift `Lyman Drop-Out' galaxies are are typically highly extincted by
dust (average factor of 5 to 10), may have moderately high metallicities (0.1
to 1 times solar?), are probably building galaxies with stellar
surface-mass-densities similar to present-day ellipticals, and may be suffering
substantial losses of metal-enriched gas that can `pollute' the inter-galactic
medium. I also discuss UV observations of the nuclei of type 2 Seyfert
galaxies. These show that compact (100-pc-scale) heavily-reddened starbursts
are the source of most of the `featureless continuum' in UV-bright Seyfert 2
nuclei, and are an energetically significant component in these objects.
