Producing software is not an easy or cheap task. Even if the software was created using free tools, by someone working for free, and then distributed for free, there was still an awful lot of time and effort (and, yes, personal funds) that have gone into producing the end result.
The free software - yes, that's given away for free. But if you'd like to make a small donation to recognise the effort involved, support the programmer, encourage development, cover costs, or just to say thanks, sending a no-strings-attached "tip" is one way that's very much appreciated.
I run several game servers, and chop and change the games that they run all the time. Popular games, where people stay friendly, I enjoy playing, and the servers aren't too much trouble, I leave running. But they all cost money. If you're a regular, and you appreciate my servers, a small donation is a nice way to show your appreciation and keep the popular servers running. But it's not necessary. I don't like to take money for them in a regular arrangement (e.g. clans, etc.), because then I would feel obliged to keep running them for ever. When a game dies, or money is short, I cull unpopular servers.
An email of appreciation will do just as well, if you have no money to give.
How to donate
There's a paypal button on the left.
A BitCoin address you can also use to donate to me is: