$ sudo apt-get update
$ sudo apt-get install gnu-smalltalk-browser 

gnu-smalltalk-browser is installed in your system.

Make ensure the gnu-smalltalk-browser package were installed using the commands given below,

$ sudo dpkg-query -l | grep gnu-smalltalk-browser *

You will get with gnu-smalltalk-browser package name, version, architecture and description in a table

gnu-smalltalk-browser package basic information: