MutableList<String> list = Lists.mutable.with("One", "Two", "Three"); list.add("Four"); list.remove("Two"); ImmutableMap<String, Integer> map = Maps.immutable.with("One", 1, "Two", 2, "Three", 3); int value = map.get("Two"); <dependency> <groupId>org.eclipse.collections</groupId> <artifactId>eclipse-collections</artifactId> </dependency> dependencies { }