JsDOSBox is a JavaScript port of jDosbox (https://sourceforge.net/projects/jdosbox/) which is itself a port of DOSBox (http://www.sourceforge.net/projects/dosbox).
Demonstration of JsDOSBox at
http://jsdosbox.sourceforge.net
Running a game demo at http://jsdosbox.appspot.com (Chrome recommended).
And running DOS demos at http://retropcdemos.appspot.com.
See website link below for details on recent changes and instructions.
http://sourceforge.net/p/jsdosbox/home/Home/
PHPterm is a terminal/shell emulator for PHP which let's you execute shell commands just like in a shell, but all within your browser window over the HTTP protocol.
It aims to provide the look and feel of konsole, the KDE terminal.