CouchDB mastermind Damien Katz and SQLite inventor Richard Hipp created UnQL, following the general guidelines set forth by Microsoft researchers in a paper published earlier this year in the Association for Computing Machinery's flagship publication, Communications. The Microsoft researchers subsequently lent a hand in the development of UnQL, Phillips said.
Like SQL, UnQL was built on the foundation of relational algebra, Phillips said. This foundation should provide assurance that using the language will produce predictable and repeatable results. The Microsoft researchers "proved you can create a co-variant relationship between the SQL relationship and a language that looks like UnQL," Phillips said.
Following the model used for SQLite, the UnQL specification has been released in the public domain, with no accompanying license. "It is open for anyone to come in and participate," Phillips said.
CouchDB, SQLite and Microsoft are shepherding the project and are inviting other parties to participate. "We're not trying to drive some sort of heavyweight process," Phillips said. Future versions of both CouchDB and SQLite will support UnQL queries, their creators promise.
This version of UnQL has no relation to an identically named unstructured data query language proposed by a University of Pennsylvania researcher over a decade ago, Phillips said.