• collections parameterized to other collections, for instance Seq[Seq[Foo]]
• maps whose key is not a String
• maps whose value is an Option or a collection
• Arrays

Salat 0.0.7 and below support the following collections:

• Map
• List
• Seq

Salat 0.0.8 supports the following collection types:

• Map
  • scala.collection.Map[String, _]
  • scala.collection.mutable.Map[String, _]
  • scala.collection.immutable.Map[String, _]
• List
• Seq
  • scala.collection.Seq
  • scala.collection.mutable.Seq
  • scala.collection.immutable.Seq
• Set
  • scala.collection.Set
  • scala.collection.mutable.Set
  • scala.collection.immutable.Set
• Buffer
  • scala.collection.mutable.Buffer
  • scala.collection.mutable.ArrayBuffer
• Vector
• IndexedSeq
  • scala.collection.IndexedSeq
  • scala.collection.mutable.IndexedSeq
  • scala.collection.immutable.IndexedSeq
• Linked lists
  • scala.collection.mutable.LinkedList
  • scala.collection.mutable.DoubleLinkedList

Not yet. It's in an experimental branch while I try to consider:

• deserialization must preserve original order
• what happens to null or None entries during serialization?
• multi-dimensional arrays
• arrays of Option[_] or collections - what class manifest to use? How is this represented in the pickled Scala signature?

• scala.collection.immutable
  • HashMap
  • HashSet
  • LinearSeq
  • Queue
  • RedBlack
  • SortedMap
  • SortedSet
  • TreeMap
• scala.collection.mutable
  • HashMap
  • HashSet
  • History
  • LinearSeq
  • MultiMap
  • PriorityQueue
  • Queue
  • RevertableHistory
  • Stack
  • UnrolledBuffer
  • WeakHashMap
  • WrappedArrau