Funny Linux Commands

Source article:
http://www.tecmint.com/20-funny-commands-of-linux-or-linux-is-fun-in-terminal/
http://blog.jobbole.com/41129/

1) sl
Author: Toyoda Masashi
Source Code: https://github.com/mtoyoda/sl

2) cowsay/cowthink
Author: Scott Chacon
Source Code: https://github.com/schacon/cowsay

3) fortune
Author: Ken Arnold
Source Code: ftp://ftp.ibiblio.org/pub/linux/games/amusements/fortune/

4) cmatrix
Author: Chris Allegretta
introduction: http://www.asty.org/cmatrix/

5) telnel towel.blinkenlights.nl
Source: http://www.blinkenlights.nl/services.html

6) figlet/toilet
Source Code for figlet: https://github.com/cmatsuoka/figlet
Related articles: https://sequoia.github.io/blog/fun-with-toilet/    http://www.linux.com/learn/docs/686943-linux-tips-fun-with-figlet-and-toilet

7) xeyes
For mac, it is Jeyes
Related article: http://www.valleyprogramming.com/blog/java-xeyes-app

8) rev(reverse), factor