I don't know if people are aware of it.  If not, here is a simple trick to
see 'what has changed' between two versions of an executable:
{{
ident first_executable_version second_executable_version | sort | uniq -u
}}
For example:
{{
ident db_purge /root/ballen/boinc/sched/db_purge  | sort | uniq -u
     $Id: version_diff.txt,v 1.2 2005/01/18 23:35:50 davea Exp $
     $Id: version_diff.txt,v 1.2 2005/01/18 23:35:50 davea Exp $
}}
I find this very helpful in reviewing what has been modified in the various
BOINC daemons, when updating versions.