freeware vs vaporware

freeware

noun
  • Complete and functional software that does not require payment or other compensation (such as viewing advertising) for its use. Freeware may be a proprietary license with no access to the source code. 

vaporware

noun
  • An advertised product, often computer software, whose launch has not happened yet and might not ever happen. 

How often have the words freeware and vaporware occurred in a corpus of books? (source: Google Ngram Viewer )