Updates to the information below are welcomed, especially for distributions (including *BSD etc.) which aren't yet mentioned.
openconnect, NetworkManager-openconnect (or network-manager-openconnect) and vpnc-scripts packages are automatically built and published for all supported Linux distributions and architectures on the Open Build Service. Repositories can be added following instructions on OBS.
openconnect, NetworkManager-openconnect (or network-manager-openconnect) and vpnc-scripts packages are automatically built and published for all supported Linux distributions and architectures on the Open Build Service. Repositories can be added following instructions on OBS.
Both openconnect and NetworkManager-openconnect packages are included in Fedora and generally kept up to date with the latest release.
In addition, the latest git master branch is built automatically in the dwmw2/openconnect COPR for current versions of Fedora as well as RHEL/EPEL and also a mingw-openconnect package cross-compiled for Windows.
The openconnect and NetworkManager-openconnect (or network-manager-openconnect) packages are included in most Linux distributions.
The openconnect and network-manager-openconnect packages are included in Ubuntu but bug fixes are sometimes very slow.
There is an OpenConnect package in the NetBSD pkgsrc repository, which covers many UNIX-like systems.
An openconnect port is available for FreeBSD.
The OpenBSD ports collection contains an OpenConnect package.
The Homebrew project contains an OpenConnect package.
NSIS-based installers for OpenConnect are automatically built with each commit pushed to GitLab CI. Download the most recent build from the master branch for 32-bit Windows or for 64-bit Windows. Note that this is the OpenConnect command-line application; see GUI Tools for other possibilities.
The Fedora dwmw2/openconnect COPR mentioned above contains mingw-openconnect packages built for 32-bit and 64-bit Windows. These are in the form of Fedora RPM packages, which can be extracted via rpm2cpio to obtain the installer executable.