Publish and Subscribe (Mac OS)

Publish and Subscribe was a document linking model introduced by Apple Computer in System 7. Named the Edition Manager in developer documentation,[1] it extended the existing cut and paste editing model with a notification system; "subscribers" could include parts of "published" documents within themselves, and changes to the original published document would be noticed and updated by the subscribers. To the user the system was very similar to cut and paste in concept; material would be selected from the source document and published, creating an edition file, then placed into the subscriber by selecting that clipping file and positioning it inside the document.

In general terms the concept was very similar to Microsoft's Object Linking and Embedding system. Unlike OLE, the Edition Manager was comparatively complex from a programming standpoint. Suffering from second system effect, it included features intended to make it better than OLE, including support for non-rectangular areas, network notifications and an extensive user interface. A result of this complexity was poor uptake among developers, and applications providing Publish and Subscribe were few and far between. One of the few products to use it effectively was Claris's suite of software, including ClarisWorks which had already built a system somewhat similar in concept, but required extensive changes to make its own system work with OpenDoc.[2]

At the time many in the industry felt that the Publish and Subscribe concept was the "next big thing". Apple and Microsoft were not the only two companies trying to introduce such a system; most major software vendors attempted to introduce similar systems, and NeXTSTEP included a version. However users did not find the system useful. Further it was sometimes confusing to use; if the document included live links it was no longer possible to simply copy it to a floppy disk (for instance), the clipping file had to be copied as well. In addition, opening their applications to new component developers who would compete to provide the best editors was not attractive to large corporations such as Microsoft and Adobe.[3] Eventually most vendors simply abandoned the concept, while Microsoft re-positioned theirs as an internet browser plugin system known as ActiveX.

See also


  1. "Publish and Subscribe (MacApp PG)". Retrieved 2007-09-16.
  2. "A Brief History of ClarisWorks". One thing required was integration with OpenDoc, which necessitated a massive restructuring of the program. OpenDoc was designed to tackle a lot of the same problems that ClarisWorks tackled, and each project had its own ideas and metaphors for component integration and interface architecture.
  3. "Macintosh vs Windows 95" (PDF). Application developers will be able to focus on writing small programs that do specific things, rather than creating entire suites. This will make it much easier for small, innovative software companies to get back in the industry....OpenDoc applications will be sold the way applications are sold today, and through the same channels. But as with any new technology, additional channels will evolve to capitalize on the technology’s strengths. It is likely that over time on-line component warehouses will be used to distribute some OpenDoc applications. Interesting new on-line applications and services will be enabled by OpenDoc.
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