Editing OpenStep (section)

==Building on OpenStep==
{{Unsourced section|date=March 2023}}
The standardization on OpenStep also allowed for the creation of several new library packages that were delivered on the OPENSTEP platform. Unlike the operating system as a whole, these packages were designed to run [[Standalone program|stand-alone]] on practically any operating system. The idea was to use OpenStep code as a basis for network-wide applications running across different platforms, as opposed to using [[CORBA]] or some other system.

Primary among these packages was [[Portable Distributed Objects]] (PDO). PDO was essentially an even more "stripped down" version of OpenStep containing only the Foundation Kit technologies, combined with new libraries to provide [[remote invocation]] with very little code. Unlike OpenStep, which defined an operating system that applications would run in, under PDO the libraries were compiled into the application itself, creating a stand-alone "native" application for a particular platform. PDO was small enough to be easily portable, and versions were released for all major server vendors.

In the mid-1990s, NeXT staff took to writing in solutions to various CORBA magazine articles in a few lines of code, whereas the original article would fill several pages. Even though using PDO required the installation of a considerable amount of supporting code (Objective-C and the libraries), PDO applications were nevertheless considerably smaller than similar CORBA solutions, typically about one-half to one-third the size.

The similar '''D'OLE''' provided the same types of services, but presented the resulting objects as [[Component Object Model|COM]] objects, with the goal of allowing programmers to create COM services running on high-powered platforms, called from [[Microsoft Windows]] applications. For instance one could develop a high-powered financial modeling application using D'OLE, and then call it directly from within [[Microsoft Excel]]. When D'OLE was first released, OLE by itself only communicated between applications running on a single machine. PDO enabled NeXT to demonstrate Excel talking to other Microsoft applications across a network before Microsoft themselves were able to implement this functionality (DCOM).

Another package developed on OpenStep was [[Enterprise Objects Framework]] (EOF), a [[object-relational mapping]] product.