I'm (being a resident of Germany) going to introduce a software foundation - keep in mind though that I'm using term "software foundation" in a non-legal sense; and actually the goal of this question would be to figure out what would be correct form of organization.
The idea behind this foundation is to survive on donations, both corporate and personal, and deliver open-source solutions, most of which would be free (that is, some still will exist as a paid software but will be always open-source - so one can just compile distrib by themselves).
The question is - is there any specific form of organization I can choose and register as to minify tax expenses? I do realize that why you are making money on some of products it's a commercial activity.
Still, many of them will be non-profit by design - and if I'll have like 40% in taxes for donations - well, it will be sad.