> Developed by Format Software GmbH (Cologne, Germany) to overcome
> deficits of HyperCard. It was released for the Mac in 1989,
> distributed by Olduvai, aimed at HyperCard power-users. Plus could
> run HyperCard stacks directly, and did so slightly faster than
> HyperCard itself. However, it also added many new features. Among
> the many "wish list" features were document-like resizable and
> scrollable windows, 8-bit color support, and the ability to display
> and work with graphics files stored externally. Plus did not,
> however, provide for pull-down menu support or allow stacks to be
> compiled into stand-alone applications, features of the competing
> SuperCard.
>
> Plus was purchased by Spinnaker Software and began the process of
> porting the system to Presentation Manager (OS/2) and Microsoft
> Windows. These versions used the same file format as the original,
> meaning it was the only HyperCard clone of the era that allowed a
> single stack to be used on all supported platforms. The system was
> later purchased by the newly formed ObjectPlus in early 1994,
> dropping the Mac and OS/2 versions and releasing the greatly updated
> WinPlus 3.0 in 1994, and 3.1 in 1995. By this time, the product was
> being referred to as a multimedia system, a niche market that most
> of the HyperCard-like systems had targeted.
>
> -Wikipedia Entry
