It works fine with Varnish 4, open source version. Varnish Plus is not required.
To use this extension, a version of Varnish Cache greater than or equal to 3.0 is required to be installed, which is available on the » Varnish Cache homepage.
It works fine with Varnish 4, open source version. Varnish Plus is not required.Thank you Adrian Hernandez http://php.net/manual/en/varnish.requirements.php#115883
Yes this manual should be updated to make note of this.
may I ask simply why this requires Plus? I just lost hours implementing this only to see the extension refuses to load on my prod server :\