Philippe Archambault wrote to us that he is working on a PHP version of Radiant CMS. Radiant CMS is based on the Ruby language. Mr. Archambault has appropriately named his CMS, phpRadiant. If imitation is a sincere form of flattery, then lets hope the Radiant CMS folks are blushing!
Mr. Archambault isn't the first person to suggest taking what they liked in Radiant CMS and migrating it from the Ruby language to one that is PHP based. However, his project is the first one that I know about which has actually seen the light of day.