The xfce4-taskmanager component is an easy to use graphical task manager.
Xfce4-taskmanager documentation
See NEWS for details on changes and fixes made in the current release.
Xfce4-taskmanager archive or Xfce4-taskmanager tags
From source code repository:
% cd xfce4-taskmanager
% ./autogen.sh
% make
% make install
From release tarball:
% tar xf xfce4-taskmanager-<version>.tar.bz2
% cd xfce4-taskmanager-<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.