The Set interface inherits its methods from Collection (java.util.Collection) and contains only those methods. In addition to sets, there are queues (java.util.Queue) and maps (java.util.Map).

Eclipse Collections is a drop in replacement for the Java Collections framework. It has JDK-compatible List, Set and Map implementations with a rich API, as well as additional types not found in ...

Java’s collections like arrays and lists are foundational building blocks. Functional programming techniques are at times the ideal way to work with these collections. This article gives a tour ...

Apache Collections supports generics, so that's not a reason to choose one over the other. If the collections you need are available in it, I'd probably lean towards Guava, though.