The issue focused on high-quality computer programs and free software. This article contains information for free software users of those programs. This article also contains information for free software users of official web sites of any official web site of the National Science Foundation. This article also contains information for free software users of official web sites of any official web site of the National Science Foundation. This article also contains information for free software users of official web sites of any official web site of the National Science Foundation. This article also contains information for