Publish and Subscribe (Mac OS)

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Publish and Subscribe was a Mac OS feature from System 7 (called the Edition Manager to developers). It added a notification system to the usual cut-and-paste idea. A document could publish pieces of itself, and other documents could subscribe to those pieces. When the source changed, the published parts would update in the subscribers.

In practice, it worked like clipping: you copy material from a source, publish it as an edition, and insert that clipping into a target document. It was similar in goal to Microsoft's OLE, but more complex to program. Apple added extra capabilities—non-rectangular areas, network notifications, and a full user interface—to beat OLE. The complexity led to few applications using it. ClarisWorks was one notable example that integrated it, though adapting to OpenDoc was needed. Many thought Publish and Subscribe would be the next big thing, and other companies experimented with similar ideas (NeXTSTEP had one). But users found it not very useful and sometimes confusing—live links could complicate copying a whole document, since the clipping file also had to be copied. Large companies like Microsoft and Adobe were not eager to open their products to many new component developers.