Check existing pages about licensing and correct misleading allegations
While checking the license for another issue, I have found the following statement on the official page about TYPO3 licensing, which is IMHO completely wrong:
Extensions are essentially modifications of the original source code and therefore still fall under the GNU General Public License version 2. This means you are not allowed to sell the Extension itself directly, but you can offer to write an Extension and get paid for providing that Service instead.
This is nowhere written in GPLv2 and IMHO just wrong, since you can sell any GPLed code for any price you like as long as you provide the sources and the license for your client. So any client who bought the extension would just have the rights granted by GPLv2. He could for example sell the extension as well or just give it away for free.
Does the GPL allow me to sell copies of the program for money? Yes, the GPL allows everyone to do this. The right to sell copies is part of the definition of free software. Except in one special situation, there is no limit on what price you can charge. (The one exception is the required written offer to provide source code that must accompany binary-only release.)