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License Introduction

Outline of Open Source SW

Open Source SW means a software is open with its source code, in general, this software does not restrict reproducing, deploying, or revising itself.Well known opensource SWs are Linux kernel, Apache Web server, FireFox web browser, MySql.

Globally, Open Source has wide meaning including Free Software (no expense and no limit) defined by Free Software Foundation. However, Free SW and Open Source SW have subtle difference in terms of their history and ego. As software began to develop into a large value-added industry in the 1980s, a movement rose so that intellectual patent and license contract restrict reproducing, deploying, and revising software. Against such movement, Richard Stallman established FSF to develop Free Software movement.

However, as the word, free, in Free Software was recognized as free of charge by common people and the majority of enterprises were reluctant to participate in Free SW movement because strict GPL provisions restricted Free Software for commercial software, Eric Raymond, Bruce Perens, suggested a new expression 'Open Source' to attract more participants in source code opening.

The Open Source began to be widely used with the formation of Open Source Initiative (OSI) in charge of activating and certifying Open Source SW. OSI defines minimal standard to apply a license to Open Source, and according to this standard, certifies, manages and encourges license use.

Open Source SW License certified by OSI gets an OSI certification mark

Intellectual Property Rights and License for Open Source SW

1. Intellectual Property Rights for SW

SW is currently protected by intellectual property rights such as copyright, patent, trademark rights, and business confidentiality, as follows.


  • Copyright is a proper right given to production owner and protects the production result that the copyright is effective right away. Therefore as soon as a programmer creates a certain SW, computer copyright is effective and the right belongs to the programmer's company. No one can use the literary property without copyright holder's approval.
  • Patent

  • Patent, which is exclusive control right occurring in relation to invention, must be applied for by a legally-defined procedure and is given through examination. It is necessary to get permission from a patentee to use a patent. For SW to implement a patented system, it is necessary to get explicit permission from the patentee, regardless of programming language or source codes.
  • Trademark Rights

  • A trademark right, which is an exclusive right that allows the trademark right holder to use the registered trademark for designated goods, must be registered according to a fixed procedure before it comes into force. It is necessary to get permission from a trademark right holder to use such a trademark; using the trademark without permission results in punishment
  • Business Confidentiality

  • Unpublished SW can be protected as business confidentiality; even for published SW, idea-related part can possibly be protected as business confidentiality. But SW as business confidential can hardly be protected when it is widely opened and distributed, and a third party using it accidently cannot be legally accused.
  • 2. License and Open Source SW

    Importance of license

    Protected by three things previously mentioned, only copyright holder has the right to use, copyright holder can authorize others to perform certain behavior under specific conditions. This kind of right is commonly called license(permission to use). For example, if you purchased Windows, SW copyright holder, Microsoft lets you use the license to install Windows XP on only one computer. Thus, purchaing Windows does not mean to replicate or share the SW with others.


    Open Source SW License is the contract defining condition of term and usage between Open Source SW developer and user. In order to use the Open Source SW, user must comply with the license that developer regulated, otherwise, user would be responsible for the breach of license. The Open Source SW license basically guarantee User's free use. Reason to issue a license to Open Source SW is to make the SW developed with open source SW public under the Law. As of May 2017, OSI, managing Open Source SW license authorization, manages 78 licenses. However, only certain number of licenses are practically used. According to the Open Source Project Development web site, Freshmeat (, about 72% of 43,722 projects registered are GPL and LGPL licenses.

    3. Understanding and Use of Open Source SW License

    Open Source SW as the same as proprietary software, is legally protected by copyright; on the ground of this right, an Open Source SW copyright holder grants a license to an Open Source SW user. However, Open Source SW License is different in many ways from general proprietary SW license. Details of the license are as following. Here, licensee is one who is granted a license, and licenser is one who grants it.

  • A licensee has the free use right to the licensed Open Source SW.
  • A licensee has the free use right to replicate or redistribute the Open Source SW along with license condition.
  • A licensee has the free use right to revise the Open Source SW and can distribute the revised SW along with license condition.
  • A licensee can freely obtain and access source code of appropriate Open Source SW.
  • Open Source SW License also imposes certain responsibility on SW users. You can see details of the responsibility through license distributed together with Open Source SW. License for appropriate Open Source SW is principally specified inside source code or on homepage.

    A user who fails to meet requirements of Open Source SW License can be sued for violation of copyright (or for breach of contract) by a rightful claimant. If he or she loses the suite, the user cannot distribute SW and can bear enormous responsibilities including payment for damage. Therefore, it is important to get a clear understanding of requirements for license and prevent such situation.

    As compared with requirements defined for proprietary SW license, however, requirements of Open Source SW License are never deficit; you can reduce much more expenses than proprietary SW by understanding and observing them well. Since only a few licenses demand to open independently-developed source code, there would be little room for causing problems if you make thorough analysis before using it.

    It is therefore necessary to understand requirements for license before downloading Open Source SW for application to development. It is important to clearly analyze requirements for appropriate license and goals of using Open Source SW before starting development by asking advice of an outside expert in case independent judgment is impossible. Only this can make the best use of Open Source SW correctly and prevent possible problems in advance.

    Details of Open Source SW License

    1. Common Requirements

    Requirements for Open Source SW License somewhat vary by licenses; common requirements include Maintain Copyright-Related Passage, Prevent Product Name Overlapping, and Confirm Possibility of Coordinating SWs with Different Licenses, while optional ones include Open Source Code and Observe Patent-Related Provisions.


    Common Requirements

    Requirements for Open Source SW License somewhat vary by licenses; common requirements include Maintain Copyright-Related Passage, Prevent Product Name Overlapping, and Confirm Possibility of Coordinating SWs with Different Licenses, while optional ones include Open Source Code and Observe Patent-Related Provisions.

      Maintain Copyright-Related Passage

    • Copyright is a right that automatically occurs in relation to an expressed product when product is created. Commonly, SW stores a program name, developer, version, and contact information in source code, that are protected by such moral rights as the right of paternity and the integrity right.
    • Most open Source SW contains developer and contact information in its source code and these information may not be editable or deletable due to copyright. In particular, In particular, be careful about reciprocal licenses, such as GPL, which provide opening revision again, because of copyright infringement that reveals the developer’s information of the open source code is edited or deleted. Copyright related passages or sentences in the source code must be preserved as is and they are easily found if edited.
    • Prohibit the Duplicated Product Name

    • A SW product name is protected by a trademark right. Therefore, every open source SW should avoid using the already registered name, if not, that may cause a trademark right infringement. Particularly, some well-know open sources, (ex, Linux) already registered their name as a trade mark.
    • Confirm Possibility of Coordinating SWs with Different Licenses

    • In many cases the existing codes are used again or combined to construct SW, which can result in conflict between licenses with different codes. This is called an issue of license compatibility. Therefore, you should confirm that two licenses are compatible with each other in combining Open Source SWs distributed in different licenses.


    Specify Use

  • Many Open Source SW licenses demand to indicate that appropriate Open Source SW is used when using SW. This means definite description of use, like ‘This SW used this and this of xx open source SW. If you have a user’s manual or other media to replace the manual, make description in it
  • Open Source Code

  • Some open source licenses specify that to show codes that are edited or added in to the source code. A typical license is GPL. However, the range of the source code to be opened varies depending on License and SW development methods.
  • Patent

  • If a technology is protected by patent, you should get permission from a patentee in implementing the technology regardless of whether Open Source SW. However, if technology applying for patent uses open source SW, license brings very complicated issues to patent process. In particular, since the recently rapid increase in SW patents makes relevant problems more serious, late Open Source SWs tend to include patent-related provision in their license.