[Plugin: Add Users Sidebar Widget] question regarding functionality

I was just wondering about this plugin called “Add User Widget” that links here: http://blogs.ubc.ca/oltdev/plugins/add-user-widget/ but that link is dead. then I foudn this plugin: http://blogs.ubc.ca/support/plugins/add-user-widget/

are they identical? what exactly are their functions, I mean what are the differences?

http://wordpress.org/extend/plugins/add-users-sidebar-widget/