Currently One Identity only provides sources for syslog-ng OSE. Latest sources are available on github. On the other hand, most Linux distributions and many other platforms provide binary syslog-ng packages or easy to compile ports, and the developers of syslog-ng maintain repositories for several popular platforms.
http://www.sunfreeware.com/programlistsparc10.html#syslogng
http://www.perzl.org/aix/index.php?n=Main.Syslog-ng
https://trac.macports.org/browser/trunk/dports/sysutils/syslog-ng/
The syslog-ng Premium Edition application supports several architectures, including x86, x86_64, and SUN SPARC on a variety of operating systems: Linux, BSD, Solaris, AIX, HP-UX, Microsoft Windows (including Windows Server 2016 and Windows 10). See the complete list here.
For Windows platforms, an agent application is also available. See below for details.