Portable Distributed Objects

Portable Distributed Objects (or PDO) is a programming API for creating object oriented code that runs anywhere on a network of computers. It was created using the OpenStep system, who's use of Objective C made the package very easy to write. It was characterized by it's very light weight and high speed, things that cannot be claimed for similar systems like CORBA.

Versions of PDO were available for Solaris, HP-UX and all versions of the OPENSTEP system. A version for working with Microsoft Component object model (then known as OLE) was also available, called D'ole. It allowed you to write distributed code using PDO on any platform that would be presented on Microsoft systems as if they were local OLE objects, a powerful feature, but it did not appear to see widespread use.