Ellogon License Guidelines

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Learn more about how Ellogon is licensed and how this affects you.

Ellogon is released under the GNU Lesser General Public License (GNU LGPL).The GNU LGPL provides for a person or persons to distribute Ellogon for a fee, but not actually charging for the software itself, because Ellogon is free. Ellogon is free to share and change, but if you do change it in anyway, can you also change the license? No! The whole LGPL is devoted to ensuring this does not happen. Copyright, a much more refined and stringent law will prevent this as well.

So with regard to Ellogon, the LGPL and copyright:

You MAY distribute it and charge for that service. You MAY change it, add design and content to it and you MAY charge for that. You may NOT alter the license and you must NOT alter the copyright.

In other words, you must NOT pretend that Ellogon is yours, and you must NOT charge people for Ellogon.


Ellogon is "free" software released under the GNU Lesser General Public License (LGPL).

The word "free'' has two legitimate general meanings; it can refer either to freedom or to price. When we speak of "free software'', we're talking about freedom, not price. (Think of "free speech'', not "free beer''.)

Free software is a matter of the users' freedom to run, copy, distribute, study, change and improve the software. More precisely, it refers to four kinds of freedom, for the users of the software:

  • The freedom to run the program, for any purpose.
  • The freedom to study how the program works, and adapt it to your needs
    • Access to the source code is a precondition for this.
  • The freedom to redistribute copies so you can help your neighbour.
  • The freedom to improve the program, and release your improvements to the public, so that the whole community benefits.
    • Access to the source code is a precondition for this