I started by saying I have 2 favorite tools: Fabric for pushing app state (pure Python) and Chef for pulling/bootstraping OS/package state (pure Ruby). For more discussions on push vs. pull deployment tools, see this post of mine.
Here are the replies I got on Twitter so far:
@keyist : Fabric and Chef for me as well. use Fabric to automate uploading cookbooks+json and run chef-solo on server
@vvuksan : mcollective for control, puppet for config mgmt/OS config. Some reasons why outlined here http://j.mp/cAKarI
@RackerHacker : There is another solution besides ssh and for loops? :-P
@chris_mahan : libcloud, to pop debian stable on cloud instance, fabric to set root passwd, install python2.6.5, apt-get nginx php django fapws.
@alfredodeza : I'm biased since I wrote it, but I use Pacha: http://code.google.com/p/pacha
@tcdavis : Fabric for remote calls; distribute/pip for python packaging and deps; Makefile to eliminate any repetition.
@competentgirl : Puppet for its expandability and integration w/ other tools (ie svn)
@yashh : Fabric. bundle assets, push to bunch of servers and restart in a shot.. love it
@bitprophet : I'm biased but I use Fab scripts for everything. Was turned off by daemons/declarative/etc aspects of Chef/Puppet style systems.
@kumar303 : @bitprophet we use Cap only because we do 2-way communication with remote SSH procs. Been meaning to look at patching Fab for this
Update with more Twitter replies:
@lt_kije : cfengine on work cluster (HPC/HTC), radmind on personal systems (OpenBSD)
@zenmatt : check out devstructure, built on puppet, more natural workflow for configuring servers.
@almadcz : paver for building, fabric or debian repo for deployment, buildbot for forgetting about it.