There are several features that I like as much about this product. This includes but is not limited too; multi-tenancy support which is very handy when you have large workload in our environment with lots of documents/documents stored across different databases or schema's. Also one thing worth mentioning is how easy, fast & efficient the overall system has proved to be over the past years we've been using it - We use marklogic mainly because one can easily integrate other systems into their solution without creating any conflicts within the database itself (which sometimes happens). So far everything seems okay and there nothing else coming to my mind right now! One problem at time =) But so far no issues reported by customers regarding problems faced while working with MARKLOGIC Database solutions, it just works perfect and handles all types of scenarios well even if they become complex later on down the line. I really like how easy is to use and configure (in my case) with RDBMS or NoSql databases.Marklogic support Java API so you can integrate easily in other languages too - but not yet implemented PHP integration. It's free, open source web content management system (WCM).