Gibraltar, a Debian GNU/Linux based firewall distribution, available for download. This Gibraltar does not need to be installed on a hard disk but can be run directly from the bootable, live CD-ROM. All software packages written for Gibraltar, including the shell scripts for booting, maintaining and administering it, can be distributed under the terms of the GNU general public license. The complete, bootable ISO images of Gibraltar can be used freely but commercial distribution is restricted.
“Gibraltar,” ibiblio catalog, accessed June 1, 2023, https://www.ibiblio.org/catalog/items/show/4553.