One Microsoft Way: the world of proprietary software
Open Letter to Software Hobbyists
Days of DOS
Windows, Office, IE, Media Player
Proprietary software can be defined as software with restrictions imposed by its proprietor (owner) on its use, copying and modification. Restrictions can be
- legal - mostly defined by the license agreement, in addition to the innate copyright from its creation.
- technical - the most common is binary-only release, keeping the source code which effectively blocks closer studying or modification (closed-source software).
- combination of these two.
It is actually interesting to see how the roles of the measures have changed over time. When Bill Gates started to demand money for his software, he relied on legal means. During the DOS era with simplified copying between the widespread PCs (and no network yet) came the age of technical means - in addition to closed source, it was the heyday of various ingenious solutions in order to make unauthorized copying impossible. It ranged from non-standard diskette formats to special dongles which were inserted into the parallel or serial port in order to allow the software to work.
Types of proprietary software
As it is often said but still frequently misunderstood - "proprietary software" does not mean the same as "commercial software". All free software can be used commercially under their licenses, while there are kinds of proprietary software that cannot (e.g. "free for non-commercial use" freeware).
Rather, proprietary software can be divided into the following categories.
commercial proprietary software
Sold commercially by unit ("boxed" software; recently sometimes also by authorised download), its license agreement prescribes its users a very limited set of rights. The license is tied to the specific computer and often to the the specific user. Copying is very limited (often, users can make a single copy for backup; other copying is forbidden), reverse-engineering, closer studying, modifying and deriving new products is prohibited. Formerly, users were typically free to transfer their software from a computer to another, sometimes even allowing simultaneous use (e.g. at home and at work).
Typically used for smaller software and/or trial versions, this is proprietary software which can be freely copied (typically in its delivery form, e.g. installer), shared with others and also used for a limited period. But like the commercial proprietary solutions, it does not allow modifications and is distributed as closed-source. The free of charge use period is typically from 15 to 90 days, after which it must be registered (typically involving payment). To encourage registration, several measures are used:
- sponsor advertisements are shown either at startup or throughout the working time when not registered (adware)
- a nag screen reminding of registration is displayed for some time at startup (nagware)
- some vital functions (e.g. saving your work) are disabled when not registered (crippleware)
While some of the shareware products are fully functional regardless of registration, they become illegal to use after expiration of the trial period (protected by legal means).
This is proprietary software with zero price. Freeware and free software are different terms - not in English but in many other languages as well. Freeware can be typically freely copied and used - however, many products limit the use by purpose, the most common restriction being "free for home or non-commercial use" (in this case, commercial users need to purchase a license just as in case of commercial proprietary product). Regardless of use, reverse-engineering, studying and modifying is forbidden, just as developing new products.
Public domain, while being one of the most permissive legal categories, can be used in proprietary context. During the DOS era there were many small utilities available under PD license - but often only as binary. Second, as there is no requirement for preserving the license, public domain components can be freely used to develop a proprietary product (even some free licenses allow for proprietary derivatives (e.g. BSD, MIT or X11 license). This kind of activity is impossible with free software licenses with "strong copyleft" that forbids narrowing the users' rights).