Similar to Tumblr

.tn

.to

.tokyo

.tr

Transifex

Tripod (web hosting)

.tt

.tv

.tw

.ua

.ug

.uk

Uniform Resource Identifier

Urchin (software)

.uy

.uz

.vc

.ve

.vg

Virtual private network

Visual.ly

.vn

.vu

Vyatta