The SINUS firewall. For linux 2.2.x kernels. The only firewall under linux with a portable GUI interface, which works with JDK 1.2 under Windows, Linux, OS/2, Solaris and more. Supports NAT. (Official Site).
You can download it from the following link: https://packetstormsecurity.com/files/download/16085/sifi-20-09-1999.tar.gz
Source: https://packetstormsecurity.com/files/16085/sifi-20-09-1999.tar.gz.html