Emission-line properties and abundances in high-redshift QSOs

An increasing number of luminous QSOs are now known at very high redshift (2 > 4). These objects are of interest in the context of starbursts in that they are evidently related to early galaxy-like condensations that have undergone or are undergoing substantial star formation activity. This contribution will review the current status of our knowledge of 2 > 4 QSOs. Recent spectroscopic work suggests that heavy-element abundances in the line-emitting plasma in these objects are often greater than solar, similar to results for QSOs at z ≈ 2-3. Additional spectroscopic anomalies may characterize these objects, although these results may be influenced in subtle ways by selection effects related to discovery techniques for high redshift quasars.