The Trove library provides high speed regular and primitive collections for Java. 

The GNU Trove library has two objectives: 

1. Provide "free" (as in "free speech" and "free beer"), fast, lightweight implementations of the java.util Collections API. These implementations are designed to be pluggable replacements for their JDK equivalents.
2. Provide primitive collections with similar APIs to the above. This gap in the JDK is often addressed by using the "wrapper" classes (java.lang.Integer, java.lang.Float, etc.) with Object-based collections. For most applications, however, collections which store primitives directly will require less space and yield significant performance gains.

Trove allows both server-side and client applications to work faster and use less memory. Give it a try and discover a library you can't live without! 


Current versions: 

• Stable: 3.0.3, changes (6/3/12) 
• Experimental: none right now