  High redshift quasars mark the locations where massive galaxies are rapidly
being assembled and forming stars. There is growing evidence that quasar
environments are metal-rich out to redshifts of at least five. The gas-phase
metallicities are typically solar to several times solar, based on independent
analyses of quasar broad emission lines and intrinsic narrow absorption lines.
These results suggest that massive galaxies (e.g., galactic nuclei) experience
substantial star formation before the central quasar becomes observable. The
extent and epoch of this star formation (nominally at redshifts z > 2, but
sometimes at z > 5) are consistent with observations of old metal-rich stars in
present-day galactic nuclei/spheroids, and with standard models of galactic
chemical evolution. There is further tantalizing (but very tentative) evidence,
based on FeII/MgII broad emission line ratios, that the star formation usually
begins >0.3 Gyr before the onset of visible quasar activity. For the highest
redshift quasars, at z ~ 4.5 to ~6, this result suggests that the first major
star formation began at redshifts >6 to >10, respectively.
