バージョン調べようとするとそれぞれで確認方違ってるのでメモ。（随時更新）

# paco --version
paco-2.0.9  (28 June 2010)
Copyright (C) David Rosal 
Protected by the GNU General Public License

# cat /etc/redhat-release
CentOS release 5.6 (Final)

32bitか64bitの確認
32bitの場合「i686 i686 i386 」と表示され、64bitの場合はX86_64やamd64
# uname -a
Linux localhost 2.6.18-194.3.1.el5.028stab069.6 #1 
SMP Wed May 26 18:31:05 MSD 2010 i686 i686 i386 GNU/Linux
もしくは
# uname -i
i386

# httpd -v
Server version: Apache/2.2.3
Server built: May 4 2011 06:51:15

php --version
PHP 5.3.7RC2 (cli) (built: Jul 1 2011 18:19:27)
Copyright (c) 1997-2011 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies

# mysqladmin version -p
Enter password:
mysqladmin Ver 8.42 Distrib 5.1.52, for redhat-linux-gnu on i686
・・・
Server version 5.1.52

# sqlite3 -version
3.3.6

# python -V
Python 2.4.3

# ruby -v
ruby 1.9.2p180 (2011-02-18 revision 30909) [i686-linux]

# gem -v
1.3.7

# rails -v
Rails 3.0.9

# git --version
git version 1.7.1

# node -v
v0.4.5

# npm -v
1.0.17

# mongod --version
db version v2.0.1, pdfile version 4.5
Mon Nov 14 21:18:09 git version: 3a5cf0e2134a830d38d2d1aae7e88cac31bdd684

# tar --version
tar (GNU tar) 1.26

# nginx -v
nginx version: nginx/1.2.0