   Using opensource icons?
  I need some icons for a closed source/commercial program.May I use crystal and tango ?I don't really get the license stuff.Can I use it freely? Modify it freely? Do I have to put a notice somewhere?Anyone experience with that?   
You may use them freely, provided that you mention the license under which you use them. For crystal, you must allow your users to change the images at will with minimal difficulty. For tango, you must include a copyright notice of their choice.You may modify them freely, provided that if the modifications are distributed in any way, then they are also distributed under the same license.;  You could also check out FamFamFam if size isn't an issue.   ;  Well let's change the topic to."Do you know more opensource icon themes I could use?".32x32 or 24x24 would be nice.   