Proprietary software
[8] Bill Gates' "Open Letter to Hobbyists" in 1976 decried computer hobbyists' rampant copyright infringement of software, particularly Microsoft's Altair BASIC interpreter, and asserted that their unauthorized use hindered his ability to produce quality software.
[12] Starting in February 1983 IBM adopted an "object-code-only" model for a growing list of their software and stopped shipping much of the source code,[13][14] even to licensees.
[16] Additionally, the growing availability of millions of computers based on the same microprocessor architecture created for the first time an unfragmented and big enough market for binary distributed software.
[17] According to United States federal law, a company can restrict the parties to which it sells but it cannot prevent a buyer from reselling the product.
[32] Most of the software is covered by copyright which, along with contract law, patents, and trade secrets, provides legal basis for its owner to establish exclusive rights.
The user may agree to this contract in writing, interactively on screen (clickwrap), or by opening the box containing the software (shrink wrap licensing).
[38] Some software is specifically licensed and not sold, in order to avoid limitations of copyright such as the first-sale doctrine.
Use restrictions vary by license: Vendors typically distribute proprietary software in compiled form, usually the machine language understood by the computer's central processing unit.
They typically retain the source code, or human-readable version of the software, often written in a higher level programming language.
For example, users who have purchased a license for the Internet forum software vBulletin can modify the source for their own site but cannot redistribute it.
The source code is covered by a non-disclosure agreement or a license that allows, for example, study and modification, but not redistribution.
[45] The text-based email client Pine and certain implementations of Secure Shell are distributed with proprietary licenses that make the source code available.
Some governments fear that proprietary software may include defects or malicious features which would compromise sensitive information.
[citation needed] For example, the bytecode for programs written in Java can be easily decompiled to somewhat usable code,[citation needed] and the source code for programs written in scripting languages such as PHP or JavaScript is available at run time.
Shareware is closed-source software whose owner encourages redistribution at no cost, but which the user sometimes must pay to use after a trial period.
In some cases, software features are restricted during or after the trial period, a practice sometimes called crippleware.
[55] Any dependency on the future versions and upgrades for a proprietary software package can create vendor lock-in, entrenching a monopoly position.
[57] Proprietary software which is no longer marketed, supported or sold by its owner is called abandonware, the digital form of orphaned works.
[further explanation needed] Some of those kinds are free-of-charge downloads (freeware), some are still commercially sold (e.g. Arx Fatalis).
