The psmisc package is probably installed on almost all Debian and Ubuntu installations and contains a number of small tools related to process management on Unix systems. Namely, these are
peekfd. Below follows a short description of these useful tools.
While everybody certainly knows
killall and probably
pstree, the package also contains
peekfd, which were new to me until very recently (though I hear at least
fuser is an age-old tool. Shame on me.)
killall is exactly as evil as it sounds: it kills all processes with a given name.