The Ja.NET project provides open source Java development tools (e.g. Java 5 JDK ) and runtimes for .NET. With the help of Ja.NET's open source software, you can leverage your Java investments on .NET.
High Availability using Virtualization:
Set up two servers (main and backup). The backup should come into action when the main goes down, & should continue the operation that the main was running, exactly from the point of failure, without loss of data.