acquired package info from repodata DB: repodata/f1f85c23079e7764ad00378a9fc5d660b89a03657290e75426caf7be5b7da462-primary.sqlite.bz2
The libXt-devel package contains libraries and header files for libXt.
The libX11-devel package contains libraries and header files for libX11.
The libSM-devel package contains development files for libSM.