libxt-dev 1:1.0.5-1 (amd64 binary) in ubuntu gutsy

 libXt provides the X Toolkit Intrinsics, an abstract widget library upon
 which other toolkits are based. Xt is the basis for many toolkits, including
 the Athena widgets (Xaw), and LessTif (a Motif implementation).
 .
 This package contains the development headers for the library found in
 libxt6. Non-developers likely have little use for this package.
 .
 More information about X.Org can be found at:
 <URL:http://xorg.freedesktop.org>
 <URL:http://lists.freedesktop.org/mailman/listinfo/xorg>