Closed source is a term for software released or distributed without the corresponding source code

Source code

In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

. Generally, it means only the binaries

Binary file

A binary file is a computer file which may contain any type of data, encoded in binary form for computer storage and processing purposes; for example, computer document files containing formatted text...

 of a computer program

Computer program

A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 are distributed and the license provides no access to the program's source code

Source code

In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

. The source code of such programs might be regarded as a trade secret

Trade secret

A trade secret is a formula, practice, process, design, instrument, pattern, or compilation of information which is not generally known or reasonably ascertainable, by which a business can obtain an economic advantage over competitors or customers...

 of the company. Access to source code by third parties commonly requires the party to sign a non-disclosure agreement

Non-disclosure agreement

A non-disclosure agreement , also known as a confidentiality agreement , confidential disclosure agreement , proprietary information agreement , or secrecy agreement, is a legal contract between at least two parties that outlines confidential material, knowledge, or information that the parties...

.

See also

• Open source
  Open source
  The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
  
  
• Open source vs. closed source
  Open source vs. closed source
  Open source - the source availability model used by free and open source software - and closed source are two approaches to the distribution of software.- Background :Under the closed source model source code is not released to the public...
  
  
• Proprietary software
  Proprietary software
  Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...
  
  
• List of proprietary software for Linux