  We discuss the design and performance of TEXES, the Texas Echelon Cross
Echelle Spectrograph. TEXES is a mid-infrared (5-25 um) spectrograph with
several operating modes: high-resolution, cross-dispersed with a resolving
power of R=100,000, 0.5% spectral coverage, and a ~1.5 by 8" slit;
medium-resolution long-slit with R~15,000, 0.5% coverage, and a ~1.5 by 45"
slit; low-resolution long-slit with (delta lambda)~0.004 um, 0.25 um coverage,
and a ~1.5 by 45" slit; and source acquisition imaging with 0.33" pixels and a
25 by 25" field of view on a 3m telescope. TEXES has been used at the McDonald
Observatory 2.7m and the IRTF 3m telescopes, and has proven to be both
sensitive and versatile.
