  We construct a realistic theory of grand unification in AdS_5 truncated by
branes, in which the unified gauge symmetry is broken by boundary conditions
and the electroweak scale is generated by the AdS warp factor. We show that the
theory preserves the successful gauge coupling unification of the 4D MSSM at
leading-logarithmic level. Kaluza-Klein (KK) towers, including those of XY
gauge and colored Higgs multiplets, appear at the TeV scale, while the extra
dimension provides natural mechanisms for doublet-triplet splitting and proton
decay suppression. In one possible scenario supersymmetry is strongly broken on
the TeV brane, in which case the lightest SU(3)_C x SU(2)_L x U(1)_Y gauginos
are approximately Dirac and the mass of the lightest XY gaugino is pushed well
below that of the lowest gauge boson KK mode, improving the prospects for its
production at the LHC. The bulk Lagrangian possesses a symmetry that we call
GUT parity. If GUT parity is exact, the lightest GUT particle, most likely an
XY gaugino, is stable. Once produced in a collider, the XY gaugino hadronizes
to form mesons, some of which will be charged and visible as highly ionizing
tracks. The lightest supersymmetric particle is the gravitino of mass \sim
10^{-3} eV, which is also stable if R parity is conserved.
