This screenshot either does not contain copyright-eligible parts or visuals of copyrighted software, or the author has released it under a free license (which should be indicated beneath this notice), and as such follows the licensing guidelines for screenshots of Wikimedia Commons. You may use it freely according to its particular license. Free software license:

The copyright holder of this work allows anyone to use it for any purpose including unrestricted redistribution, commercial use, and modification. Please check the source to verify that this is correct. In particular, note that publication on the Internet, like publication by any other means, does not in itself imply permission to redistribute. Files without valid permission should be tagged with {{subst:npd}}. Usage notes: If the work requires attribution, use {{Attribution}} instead. If this is your own work, please use {{Cc-zero}} instead. Copyrighted free use //commons.wikimedia.org/wiki/File:A_House_in_California.png

Note: if the screenshot shows any work that is not a direct result of the program code itself, such as a text or graphics that are not part of the program, the license for that work must be indicated separately.