ucspi-tcp6 is a fork of Dan Bernstein's ucspi-tcp 0.88, including:

- rblsmtpd Greetdelay add-on and removal of the compiled-in default-RBL
- Felix von Leitner's's IPv6 patch ucspi-tcp-0.88-ipv6.diff19.bz2
- Jens Wehrenbrecht's IPv4 CIDR extension
- Li Minh Bui's IPv6 support for compactified IPv6 addresses and CIDR
  notation support

Homepage:
https://www.fehcom.de/ipnet/ucspi-tcp6.html
