What Is The Definition Of An "Application"?

What is the definition of an "application"? We are "applications development and delivery professionals" - surely we have this question nailed, don't we? The question keeps coming up in different contexts, and since there are many potential opinions, a blog is the perfect place to spur debate. Here are some (simplistic) questions to generate debate:

  • Is a Web page an application?
    • If not, how many Web pages does it take until I consider it an application - 10, 100, 1,000?
  • Does size matter? (Please behave yourselves with this one.)
    • Is the size of the code base a pertinent factor?
  • What about SharePoint sites, Access databases, and spreadsheets? Are they applications?
  • Where do COTS and packaged apps fit?
  • Does the technology I use affect the definition?
    • If I use a scripting language for a quick-and-dirty task, is that an application? 
  • Does SOA erode the definition of an application?
    • Do we cease thinking about applications as entities and think about them more as containers that hold collections of SOA services?
  • How does open source affect the definition?
  • How does my role affect my perception of an application?
    • Do developers and users use similar definitions?

I have my opinions - in fact I just finished a draft piece of research on it that will be published in January, but what are your opinions?