title: Are all Haskell packages compatible with each other?
body: <p>I see a lot of Haskell packages listed here:</p>
  
  <p><a href="http://hackage.haskell.org/packages/archive/pkg-list.html#cat:database" rel="nofollow">http://hackage.haskell.org/packages/archive/pkg-list.html#cat:database</a></p>
  
  <p>Are all these packages compatible with each other? If I bring in say 10 packages in order to make a program, are they all going to be OK. What if I brought in all packages listed on the page?</p>
  
  <p>Imagine if you are in Java, in Java if you bring in say 10 jar's from around the web, there maybe dependancies between the JAR's that mean that one JAR requires a version other another JAR that is not a good version for a different JAR. For example, one JAR may need Hibernate version 3.0.0 and another needs Hibernate 2.0.0. So I cannot use these two jars because they don't use a common equal Hibernate version.</p>