All content of these sites is under free licenses, except where explicitely noted otherwise.
This means you can use my works however you want (even commercially), as long as you allow and enable others (and me) the same with all the works you create from or using parts of my works, and say who created and modified the original works.
The works must stay under the same license(s).
To use them, you can (for example) just put this license text alongside them (i.e. as html page) and create a link pointing to it. Other possibilities can (later) be found below.
More exactly: My works can be used (depending on the type of content) under the following free licenses:
Programs/Applications are only avaible under the GPL, other content under all four licenses.
I keep the right to relicense all content on these sites under other licenses, as long as those other licenses make sure that the "four freedoms" are being kept.
I use four licenses to avoid walking into a license trap (having all content under a dead license). Please also keep all four licenses when you work with content from these sites.
More detailed info can be found on the german version of this site.