OpenConnect is a free and open-source cross-platform multi-protocol virtual private network (VPN) client software which implement secure point-to-point connections.
The OpenConnect client supports the following VPN protocols:
It was originally written as an open-source replacement for Cisco's proprietary AnyConnect SSL VPN client, which is supported by several Cisco routers.
As of July 2023, support for several other proprietary VPN protocols is desired or in development: