Open Source Software is not a brand of software: It is a philosophy of software development. Programs written under this philosophy are released with the human-readable program code such that anyone is free to use it and improve it. There is much more that could be said about this subject, but the following definition, while slightly technical in nature, sums up Open Source quite nicely.
Please Note: Links in the definition below will take you to other sites that are not under our control. We try to maintain working links, but we cannot guarantee the activities of other sites. Please notify Systuff of non-working links
According to the Open Source Initiative:
Version 1.9 Open source doesn't just mean access to the source code. The
distribution terms of open-source software must comply with the
following criteria:
The license shall not restrict any party from selling or giving away the
software as a component of an aggregate software distribution containing
programs from several different sources. The license shall not require a
royalty or other fee for such sale. The program must include source code, and must allow distribution in
source code as well as compiled form. Where some form of a product is
not distributed with source code, there must be a well-publicized
means of obtaining the source code for no more than a reasonable
reproduction cost–preferably, downloading via the Internet without
charge. The source code must be the preferred form in which a
programmer would modify the program. Deliberately obfuscated source
code is not allowed. Intermediate forms such as the output of a
preprocessor or translator are not allowed. The license must allow modifications and derived works, and must allow
them to be distributed under the same terms as the license of the original
software. The license may restrict source-code from being distributed in modified
form only if the license allows the distribution of "patch files" with
the source code for the purpose of modifying the program at build time.
The license must explicitly permit distribution of software built from
modified source code. The license may require derived works to carry a
different name or version number from the original software. The license must not discriminate against any person or group of persons. The license must not restrict anyone from making use of the program in
a specific field of endeavor. For example, it may not restrict the program
from being used in a business, or from being used for genetic research. The rights attached to the program must apply to all to whom the program
is redistributed without the need for execution of an additional license
by those parties. The rights attached to the program must not depend on the program's being
part of a particular software distribution. If the program is extracted
from that distribution and used or distributed within the terms of the
program's license, all parties to whom the program is redistributed should
have the same rights as those that are granted in conjunction with the
original software distribution. The license must not place restrictions on other software that is
distributed along with the licensed software. For example, the
license must not insist that all other programs distributed on the
same medium must be open-source software.The Open Source Definition
The change history is available
here.Introduction
1. Free Redistribution
2. Source Code
3. Derived Works
4. Integrity of The Author's Source Code
5. No Discrimination Against Persons or Groups
6. No Discrimination Against Fields of Endeavor
7. Distribution of License
8. License Must Not Be Specific to a Product
9. The License Must Not Restrict Other Software