$ sudo apt-get remove gforge 

Uninstall gforge including dependent package

If you would like to remove gforge and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove gforge 

Use Purging gforge

If you use with purge options to gforge package all the configuration and dependent packages will be removed.

$ sudo apt-get purge gforge 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove gforge 

See Also,