IPv6, the Internet Protocol version 6, was decided to be designed, ten years ago, in order to replace the current version. It has now been almost completely specified and several implementations have been written for different platforms. However it is not widely used so far. One reason for this is the unavailability of softwares that can deal with IPv6. Thus the large use of the new protocol will only happen when enough attractive applications will be available. In this report, we present two Java tools that are designed to ease the development of IPv6-able softwares. We concentrated our work on Java-written software because the use of this language is growing in a lot of network-based domains: distributed systems, parallel computing, high-performance computing, network management, active networks... The first tool is a Java package that provides all the functionalities required to deal with IPv6. It has been designed with two main characteristics in mind. The first is the necessity for the underlying mechanisms to be very similar to the original ones. The second is to enable an easy transition between the code of an IPv4 software and its IPv6 counterpart. The second tool is an IPv6-able JVM, Java TM Virtual Machine. It gives every Java program the ability to deal simultaneously with IPv6 and IPv4, without any code modification.