$ sudo apt-get update
$ sudo apt-get install erlang-mochiweb 

erlang-mochiweb is installed in your system.

Make ensure the erlang-mochiweb package were installed using the commands given below,

$ sudo dpkg-query -l | grep erlang-mochiweb *

You will get with erlang-mochiweb package name, version, architecture and description in a table

erlang-mochiweb package basic information: