Most of the software components on this site are released under the GNU General Public license (GNU GPL). Here is a quick overview of what you can and can't do:
  • You may distribute it and charge for that service.
  • You may change it, add design and content to it and you may charge for these changes.
  • You may not alter the license or the copyright notice.
  • You do not have to visually show recognition of the use of this software in any application that uses it (e.g. you do not need to show something like a Powered by yet another of Gerrit's famous software components logo), as this sort of thing is not a copyright notice.
In other words, you may not pretend that GPL'd software is yours and you may not charge people for it. By all means, charge for the value you add by integrating any of these components on projects, but do not charge for the hard work that others have already put into it.


All the software available on this site "free" software released under the GNU General Public License (GPL).
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.
Access to the source code is a precondition for this.


1. What license are these software components and documents released under?
Most of the software components and documents are released under the GNU GPL. A copy of this is included with your copy of the downloaded software and can also be found on this site or at Unofficial translations can also be found at
2. Who owns the copyright to this software?
The copyright to this software is held by Gerrit Hoekstra (UK). Gerrit ("for he is a bastard, so they say") is the original author of the software components and documentation and will continue to actively support these components. A prod is sometimes required.
3. Are there any restrictions to your use of this software?
The GNU GPL grants you the freedom to use the software for whatever purpose you see fit. Incidentally, Gerrit would prefer to you to use the software for peaceful rather than beligerent purposes, democratic rather than dictactorial causes (are you reading this, Tony Blair - you lying little twerp?) and for environmentally-friendly rather than environmentally-destructive uses.

4. May I charge money for this software?
The GPL allows everyone the freedom to do this. The right to charge money to distribute these software components  is part of the definition of "free" software. When people think of "selling software'', they usually imagine doing it the way most companies do it: making the software proprietary rather than free. So to avoid ambiguity you may you may charge to distribute the software and any other service you provide along the way. You may not charge for the software itself. Remember that if someone does pays you a distribution fee, the GPL gives him or her the freedom to pass on the software with or without a fee.
5. May I remove the "copyright" statements from the source code?
No. Nein. Nyet. Nee. Non. Cha. Ne. Nei. Aikhona. Nö. Gaan kak in die mielies. You must keep all copyright notices and credits in the source code in tact.
6. Does the GPL mean that my implementation is also GPL?
No. The copyright and license of this software only does not cover the implementation that you create. Using this code does not place any legal restrictions on the license or copyright you use in your intended target application.
7. I have modified this code for my own implementation. Do I have to release these modifications?
The GPL permits anyone to make a modified version for their own use without the requirement to distribute it or pass on those changes to others.
8. I have made a modification (hack) to the code. Do I have to release it under the GPL?
If you chose to distribute your modifications to others it must be released under the same terms that you received the original code. So your modifications must be released under the GPL. You may of course in this case modify the headers for the source code to additionally include your own copyright statement. If you do so you must clearly annotate in the source code your amendments, changes or additions.
9. I have written a User interface / Wrapper around one of these components. Do I have to release it under the GPL?
No. The GPL allows you to write your own extensions and to release those extensions under whatever license you chose.
10. I have written a User Interface / Wrapper and released it under the GPL and I charge a fee for it, but website X is giving it away for free.
If someone pays your fee the GPL also gives him or her the freedom to pass on the software with or without a fee. Placing a restriction on someone's use of GPL licensed software is in breach of the GPL itself.
11. May I purchase a copy of one of these components, which has the copyright statements removed?
It's a funny old world - some people feel a lot better having paid vast sums of money for something that they could get for free. So, sure, if the money burns a hole in your pocket, go for it!  But expect that an onerous license, typical found with closed-source software, will be imposed on you. That's what you want, right?
12. I believe person A is in breach of the GPL what should I do?
You should report it. First check all the facts where you can and then report it by sending an e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it.. Gerrit ("for he is the champion, laah-la-la-laah-la") will take it from there.
13. Who has the power to enforce the GNU GPL license of any of these components?
Only the copyright holder, Gerrit Hoekstra (UK), has the power to do this.
14. Vendor X is using, or offering, my non-GPL User Interface / Wrapper without my permission, or in breach of its license, can you help me?
Whilst this is not within my remit nor my responsibility, I am willing to act as intermediary in this on your behalf. In most cases these situations arise out of simple misunderstandings and can be settled amicably.


This document refers to the software and documentation that was created by Gerrit Hoekstra (UK) available for download on this site and released under the GNU General Public License and copyrighted to Gerrit Hoekstra (UK). This document is subject to additions, modifications and other changes at any time without notice. A lawyer has not prepared this document. They are scum in any case. You should consult a lawyer experienced in copyright, licensing and intellectual property for clarification. If you can find an honest one.