When you buy my software, you can use it forever, on as many sites as you like. The price is not a licence, it is to pay for the time I spend on upgrades and support. If you don't need to upgrade, and you don't need support, you can use the software that you download from me for as long as you like, even after your downloading and support period expires.
I'm always working on something. People are always sending me good ideas, and while I make no commitment whatsoever to do anything at all, I often do add new functionality to my extensions. So for my non-free products I offer a choice of payment options that include more, or less, upgrade options.
Downloads
When you buy downloads from me, you buy a number of downloads (for that product) valid for a certain length of time. I send you a personalised link that you can use until you have exhausted your downloads or your time limit, whichever happens first.
Please note that each product is priced and purchased separately. You can't use downloads for one product to download a different product. My products are all very different and very few people use more than one, so the idea is that you only pay for what you need.v
Licensing
All my Joomla extensions are Free Open Source Software. In this context, "free" refers to the freedom to copy and re-use the software, and not to the price of the software. Basically, you are allowed to use it in any way you like, for as long as you like, on as many systems as you like.
I use the GNU General Public License version 2, which gives you legal permission to copy, distribute and/or modify the software. Any developers who try to restrict these freedoms are not complying with the GPLv2 and cannot advertise their extensions on the Joomla Extensions Directory. There is more information about that here.
The only thing I ask of you is that you do not make our paid works publicly available. That would severely reduce my ability to sell them, which would destroy my incentive to continue to develop and support them. That would help no-one. So far, this arrangement appears to be generally understood and respected for Free Open Source Software.
I am allowed to apply copyright to my documentation and to restrict your rights to copy, duplicate, or redistribute it. Please respect the copyright of my documentation.