http://www.geocities.com/jmzoneus/ is the current location, but Mada is working on a new page, and it'll be moving to his domain name then.
As for the editor - it's likely there will be a version of EFRadiant for it. Thats mildly disappointing, as GTKRadiant had gone a long way since EF was released and I don't know what state EFRad is in. (I've never used it. My EF cd is in two pieces somewhere under a bookshelf.)