scala-xml 
The standard Scala XML library.
As of Scala 2.11, this library is a separate jar that can be omitted from Scala projects that do not use XML. We're also looking forward to alternative implementations!
API documentation is available here.
Adding an SBT dependency
To depend on scala-xml in SBT, add something like this to your build.sbt:
libraryDependencies += "org.scala-lang.modules" %% "scala-xml" % "1.0.2"
(Assuming you're using a scalaVersion for which a scala-xml is published.
The first 2.11 milestone for which this is true is 2.11.0-M4.)
To support multiple Scala versions, see the example in https://github.com/scala/scala-module-dependency-sample.