To use isgnu, run the command 'chmod +x isgnu' from within this folder once you've cloned it. isgnu works internally by pinging one of two possible gnu project formats on the gnu site: gnu_url/project_name or gnu_url/project_name.README. isgnu does not cache, and isgnu does not have any options. isgnu pings using one of two commands, depending on which is installed on your system. First it looks for curl, and if it doesn't find this it uses wget. The format of the command is 'isgnu PROG_NAME' where PROG_NAME is the name of the program being checked if gnu. Have fun!