There are a variety of methods available to determine which version of EZproxy is running on your server.
If you are running EZproxy for Linux or Solaris, you can issue a command like:
changing /usr/local/ezproxy/ to the directory where EZproxy is installed.
If you are running EZproxy for Windows, you can issue a command like:
changing c:\ezproxy\ to the directory where EZproxy is installed.
With EZproxy for Windows, you can right-click on the ezproxy.exe file, select Properties, and go to the Version tab. Starting with EZproxy 2.4, the complete EZproxy version appears in the description. For older versions, you need to look in the "Other version information" section of this page and to find and click on "Product Version" to get the complete EZproxy version.
The version appears on the EZproxy Administration page.