While I can't go into too much detail about what they do, I run several Perl programs as daemons because they must react near immediately. They process FTP upload traffic, email, pages, logs, interact with databases, watch for weirdness, etc. They've been running since Sept 2003. One has processed 45K transactions, another 365K, from just January thru June.

Four out of the five below haven't grown a bit. The fifth has grown about 1.5MB since September, and that's called a bug. There are tools to help with bugs like that.

(Highly boiled down 'ps' output to not mess up web pages)

  PID  PPID   VSZ   STARTED                  COMMAND
 2743     1   4200  Thu Sep 11 17:51:08 2003 budgdmon.pl
      budgdmon: waiting
 2803     1   5044  Thu Sep 11 17:51:09 2003 budgftpd.pl
      budgftpd: waiting
 2850     1   4308  Thu Sep 11 17:51:12 2003 pageqrdr.pl
      pageqrdr: waiting
 5810  5807   7040  Thu Sep 11 18:11:31 2003 perl
      perl -w /opt/budgie/admin/xflogger/xfsuck.pl -v -d 
            --database test --table XferlogX 
            --fromtail /var/log/xferlog
 6815  6814   4420  Thu Sep 11 18:17:03 2003 perl
      perl ModemMonitor.pl

Now not all the processing takes place within the daemons. They do spawn off tasks for lengthy and/or nasty processing, so that probably contributes to the lack of problems _within_ the daemons.

My take - Perl is "very fine" for writing daemons.