  Detailed spectral classifications are presented for 352 O-B0 stars in the
VLT-FLAMES Tarantula Survey, of which 213 O-type are of sufficient quality for
further morphological analysis. Among them, six subcategories of special
interest are distinguished. (1) Several new examples of the earliest spectral
types O2-O3 have been found. (2) A group of extremely rapidly rotating
main-sequence objects has been isolated, including the largest $v\sin i$ values
known, the spatial and radial-velocity distributions of which suggest ejection
from the two principal ionizing clusters. (3) Several new examples of the
evolved, rapidly rotating Onfp class show similar evidence. (4) No fewer than
48 members of the Vz category, hypothesized to be on or near the ZAMS, are
found in this sample; in contrast to the rapid rotators, they are strongly
concentrated to the ionizing clusters, supporting their interpretation as very
young objects, as do their relatively faint absolute magnitudes. (5) A
surprisingly large fraction of the main-sequence spectra belong to the recently
recognized V((fc)) class, with C III emission lines of similar strength to the
usual N III in V((f)) spectra; there are also six objects with very
high-quality data but no trace of either mission feature, presenting new
challenges to physical interpretations. (6) Five spectra with morphologically
enhanced nitrogen lines have been detected. Absolute visual magnitudes have
been derived for each star with individual extinction laws, and composite HRDs
provide evidence of the multiple generations present in this field.
Associations with X-ray sources are noted. Further analyses of this unique
dataset underway will provide new insights into the evolution of massive stars
and starburst clusters.
