I only use CVS, GIT, HG, and SVN to pull source codes from repositories. With GIT, I can check pull the current HEAD from the repository (i.e. git ls-remote URL HEAD) and compare it with mine to see if it is necessary to do a git pull to update my local source from the repository. With SVN, it is a bit trickier (i.e. svn info URL | sed -ne's/^Revision: //p'). With CVS and HG, I have no idea. However, I sure would like to know how to achieve the same thing with HG. Anyone?