A live DEMO of PHPki is available at this site. There are some minor differences between this demo and the download version.
With this DEMO you may switch between the public content and private certificate management sections of the application. In the download version, the private section is not accessible from the public section and vice-versa. Sourceforge does not allow this application to be installed in "secure" mode. Therefor SSL/HTTPS access, and HTTP authentication for multi-user modes are not available.
I have had difficulty with this web server's responsiveness. It sometimes seems to drop packets or not deliver content. You may have to refresh your browser frequently. Sorry, I guess Sourceforge is popular and busy.