Here is a collection of software called LOOP!

List Of Open-source Programs (LOOP) for Microsoft Windows Operating Systems

• This is a list of the best open-source applications that run o­n Windows.
  
  The purpose of this list is to demonstrate the quality of open-source applications and advocate the open source software development model.
  
  " o­n this list you will find free, high-quality replacements for the software that they have purchased/pirated. o­nce they become familiar with these new applications, introduce them to your favorite Linux distribution, such as Ubuntu. Then help them convert to Linux, using the same applications that they became familiar with o­n Windows. "