What you need

Before you can begin developing an application in Java for .NET, you need to download the Ja.NET SE development kit from our download center.  It includes all the necessary tools required to develop and run Java-based applications on .NET.  

Also, should you want to develop and run your Java code on a standard Java platform, Ja.NET SE also includes Apache Harmony, an open source Java platform developed as a project of the Apache Software Foundation.   The combination of these two in Ja.NET SE gives you the ability to develop and run Java-based applications on both a standard Java platform as well as .NET.

What's available

Just like with other Java platforms, Ja.NET SE comes in two packaged forms: The Java Runtime Environment (JRE) and the Java Development Kit (JDK).

• Ja.NET SE Runtime Environment - Includes the Java APIs, two Java Virtual Machines, and other pieces needed to run applications developed in Java on both the standard Java platform and the .NET platform.
• Ja.NET SE Development Kit - Includes the entire runtime environment and additional development tools (e.g., compiler, bam, etc.) needed to develop applications in Java for both a standard Java platform as well as .NET.

Downloads are available in two formats: a .ZIP file or an installable .MSI file. The easiest way to install Ja.NET SE is to download and install it using the .MSI file. If you prefer greater control, you can download and configure the components yourself using the .ZIP distribution.  We provide detailed instructions for installing and configuring Ja.NET SE on our installation page.

What you get

The Ja.NET Development Kit includes three main components:

• Java Development Tools - This includes command line-based development tools such as the Java compiler (javac), Java launcher (java), and the build assembly module (bam) tool. Most of the tools can be used to develop and run software written in Java on either the standard Java platform included with Ja.NET SE, or the .NET platform. In most cases, you control what platform you want to target and run on using command line options when invoking the tools.
• Java Virtual Machine (JVM) - Ja.NET SE includes two virtual machines. The first is a JVM based on the Apache Harmony DRLVM. It provides you with a standard Java platform which you can use to develop and run applications. The second is the Ja.NET SE JVM Adapter. It provides you the ability to run Java-based applications developed using Ja.NET SE on the .NET virtual machine (CLR).
• Java APIs - Ja.NET SE includes two sets of Java 5 class libraries. The first set are class libraries built  for the standard Java platform included in SE (i.e., Apache Harmony). The second are class libraries specially built for running applications on .NET.   At this point, the .NET version of the APIs are not 100% complete, but work is underway to fill out the entire API set.