What was the first home computer and file system that allowed users to choose freely between 3rd party applications?
I was under the impression that early PC (manufacturer) bundled their own applications (like word processor or spreadsheet program) without any means to have another application be used instead. Was this the case? If so, what was the nature of the change toward allowing users to grant third party applications the same privileges?
which allowed the user to choose freely between 3rd party applications in opening data files.
and (from a comment)
I was under the impression that early PCs bundled their own applications (like word processor or spreadsheet program) without any means to have another application be used in its place (or documented means?). Was this the case? If so, what was the nature of the change toward allowing users to grant third party applications the same privileges? Thanks
The Answer is simply every OS and every PC.
Back in ye good ol' days OSes were way too primitive to even try something like a closed system. They where merely loaders to start some application.
Early microcomputers were complete open systems. Home computers and later PCs even more so. The first such were bare hardware, delivered without an OS. If at all, only a monitor program was supplied – sometimes as small as 256 Bytes, offering nothing more than a chance to examine and change memory locations. The Altair for example was delivered completely without anything. Programs had to be entered bit by bit via switches. Not too much of a hassle considering that the main memory was just 256 bytes.
Any OS would have to be either user written, or bought in addition. Even more so applications. While home computers like PET, TRS-80 or Apple II became soon more lavish, they still only supplied some frugal (by today's standards) monitor and BASIC as high level language and OS. OSes more like today only became available after disk drives where sold. Still manufacturers did only offer a DOS and, if at all, a very limited selection of software, mostly restricted to languages and tools. Or in case of home computers like Atari 800 maybe some games. The majority of applications where third party.
Similar there where OSes for each of these machines by third party suppliers. Usually due the fact that the original DOS was rather limited (*1). The market was quite open, and maybe except for some strange people no one could imagine what a closed system would be good for. In fact, even the idea of bundling was not much thought about.
The first (successful) machine with an application package included was the (professional) Osborne 1 of 1981. Here wordprocessor, spreadsheet, database and BASIC was bundled with an OS. Still, the OS was CP/M, an open, manufacturer independent OS, open to any kind of third party application.
Another kind fitting your idea would be early handheld LCD portables like the Kyotronic 85 family (Tandy M100, Olivetti M-10, NEC PC-8201, NEC PC-8300). They came with applications preinstalled in ROM - much like todays phones. Again, it wasn't about convenience, but the convenience of instant on usability. They could as well install third party applications in RAM - some even got user accessible ROM slots to install third party ROM based applications.
Without being open to third party software, computers might not have been the success they are at all.
*1 - Check for example NewDOS for the TRS-80
While there were a few systems that associated data closely to integrated applications, they were few and far between, and generally speaking were, for the most part, not what you'd usually consider a "home computer".
The best known, I suspect, was the Xerox Star. The Star was the first truly commercial system to be built with what we'd recognise today as a standard GUI (it was the successor of Xerox's research system, the Alto, which was never sold commercially in anything other than a half-hearted way). It had many, many innovative new ideas (including a WYSIWYG word processor, a system for embedding objects produced by one application inside a document managed by another, a "desktop" interface, icons, and so on). It also had a file system that tracked the creator of each file, so that if you clicked on the file's icon it would open it in the application that created it. It was also designed to be supplied with a set of standard applications and not be end-user extendable, so it does exactly match the kind of interface you're looking for.
The only thing is, you wouldn't really call it a home computer: Xerox never really marketed it other than to large businesses, so they never became popular enough that individuals wanted to buy them. They also cost well in excess of an average person's annual salary. In the year the IBM PC went on the market at $1,600, they sold for $16,000.
The Alto and the Star had, however, inspired a number of other people to produce similar systems. The most popular of these was the Apple Mac, which used the same system of associating a file with its creator in order to allow it to be automatically opened when the file's icon was clicked. The Mac was much closer to what you'd call a home system, but didn't have the closed ecosystem: it allowed (and in fact Apple encouraged the development of) new applications, and as any application could register the types of data it could work with, the system would allow the user to change what application would be used for any particular file just by selecting them from a list.
Other systems followed Apple's lead: Microsoft Windows switched from application-based interface to document-based in version 3 (IIRC), using file extensions to associate applications via a list stored in the win.ini file (which was, of course, easily modified to add new applications, but didn't provide any easy way of supporting a file type that could work with multiple applications), and other systems like the Commodore Amiga or Acorn's RiscOS also implemented similar mechanisms.
Another common type of system where data was associated directly with applications was in portable/"palmtop" computers, e.g. the Psion Organiser, which (at least in early versions) either didn't support additional applications or were difficult to develop for so few applications became available. Such systems only really became truly flexible in the 90s, with systems like the PalmPilot (which directly copied many parts of the Apple Mac user interface and API, including its use of 4-character codes to identify data types) and Microsoft's Windows CE being among the first to have many third party applications.
