title: Removing unused libraries without breaking the code
body: <p>Over the years, our project has used many different libraries. I'm pretty sure some of them are not used anymore, while others are obsolete and should be upgraded.</p>
  
  <p>I am looking for tool to find which libraries (jar files) are no longer used and can be removed. I could also use some help to find out which libraries should be upgraded -- at least when I swap jar file with newer version, I would like to get report saying that there are now incompatibilities (wrong method signatures, unknown classes, ...).</p>
  
  <p>Is there tool like that?</p>
  
  <p>We don't use Maven or Ivy or any other dependency management system. We have tests, but they don't cover everything.</p>