exo is an extension library used in the Xfce desktop. It has some helper applications that are used throughout the entire desktop, to manage preferred applications and edit .desktop files.
See NEWS for details on changes and fixes made in the current release.
From source:
% cd exo
% ./autogen.sh
% make
% make install
From release tarball:
% tar xf exo-<version>.tar.bz2
% cd exo-<version>
% ./configure
% make
% make install
Visit the reporting bugs page to view currently open bug reports and instructions on reporting new bugs or submitting bugfixes.