Found 3 packages
J2N is a library that helps bridge the gap between .NET and Java. It provides components to assist with porting Java code to .NET, such as collections, adapters, and extensions. It contains some features from Java that also make it generally useful in any .NET application.
The System.Collections namespace in the .NET Framework provides a number of collection types that are extremely useful for manipulating data in memory. However, some specialized implementations of ISet are not available. Iesi.Collections 4.0 for .Net 4.0 contains the LinkedHashSet (preserves insertion order), the ReadOnlySet and the SynchronizedSet. The latter two wrap an actual set.
RockHouse.Collections is a Collection class package that mimics the Java language API and the Apache.Commons.CollectionsAPI. It also adds several proprietary APIs.