IIOP.NET is an opensource project that provides seamless interoperability between .NET and J2EE based on RMI/IIOP. It provides an IIOP .NET Remoting Channel implementation and IDL compilers for C#.

Patrik Reali has posted an article on The Code Project showing a Java client accesing a RMI server coded in C#.

Check out The Code Project

Maybe Patrik Reali has not choosed the best example in his post, because I don´t think that will be very usual to build servers on .NET and fat clients on Java. In our case, we are willing to do exactly the opposite. We want the escalability and integration capabilities of J2EE on the server side and, as our corporate desktops are running Windows, we also want MS efficient developer tools and attractive graphical interface of .NET on fat clients.

The biggest problem we have with this architecture is interoperability. The official way is Web Services, but despite Web Services could be the best solution from a developer's point of view, its resource hungryness translates in hardware costs that we want to save. The alternative was building a propietary protocol, but propietary solutions only will bring us problems in the future.

We found IIOP.NET by chance, and started compatibility and performance tests with WAS 4 and 5. After some initial problems, and thanks to the collaboration of lead IIOP.NET developer Dominic Ullmann IIOP.NET has become a serious alternative for our integration problem.

Other projects providing .NET and J2EE interoperability based on .NET are Remoting.Corba and Borland Janeva.

The other product is JNBridge

Another very good product is Janeva from Borland.

One more...one of the first comers in this category..

Halcyon's iNET.."Write Once in .NET, Run Anywhere"

http://www.halcyonsoft.com/products.asp?s=4

When I first tested it with Wesphere 4 it did not work at all. I tried to get support on borland newsgroups but though there's a Janeva group, it's so new that the only thing discussed there was the convenience of "Janeva" as a brand name. But yesterday a guy from Borland replied to me and told me that I need a 1.3 j3ee server and will be a Websphere 5 certified version later on this year.

  Now we are also going to test Janeva for our project. We trust on everything Borland makes so it will be sure a good alternative.

>
>   Now we are also going to test Janeva for our project. We trust on everything Borland makes so it will be sure a good alternative.

You may want to contact your local Borland office. We have special
resources (i.e. technical consultants) to help you during your
evaluation/tests.

Office list

Janeva main page

Best regards,

Marc Weiersmuller
Solutions Architect
Borland UK

Also Ja.NET from Intrinsyc, provides Java/.Net interrop through a pure Java implementation of the .Net remoting protocol. It's bi directional as well, and you can use soap/binary on the fly as well.

http://ja.net.intrinsyc.com

I've read JNBridge and Intrinsys Ja.NET docs, as both are recommended by MS as interop solutions (at pass TechEd). But both them use propietary protocols, not RMI/IIOP, so it mandatory to install "proxys" on the Java side.

Out of interest: Is Eduardo Macarron Miegemolle your real name?

  Yours is an interesting question Bob. Yes it´s my real name. Othe out of interest: Why your interest about it??

No offense. I think it is just the most interesting sounding name I ever encountered in my life. It's unbelievable - a wickedly cool combination!

lol! Yes it's an extrange combination. It sounds like a mix between spanish, italian and french names. Well Miegemolle is indeed a french surname inherited from my grandfather. But despite it may seem, Macarron is an spanish surname, so my name is not so international :)

For years we have been constantly battling the stage of interoperability between platforms. The times are now changing where the camps are now talking more, which is a plus for us developers. With products like Janeva that let us choose which platform to use for the client and the server we can mold our development technologies to suit and not be tied down to specific vendors with bridging technologies. I only hope that Borland do not ask too much for the deployment licences!! Mr Gates, please reduce those license costs and the size required for C#.NET deployment.

I can see this product as a good stepping stone with the backbone of IIOP which is now mature enough and has weathered all the storms. There is no conflict that I see between this type of technology and Web Services. Too me Web Services are suited for particular cases full stop. And we all know that many have been caught up in the marketing hype with XML and web services, which still uses too much memory resources(apologies to the hard end WS guru's). C# has been a good response from Microsoft (ie java, C++ plus a bit extra without those pointers!) and I am glad that the guy who led it came from the Java development side of Borland.

With more giving between Sun, Microsoft, Borland, BEA, IBM, etc we will find a much better working environment. Some say, take my rose coloured glasses off but heh, everthing starts with a little faith.

My business will be buiding C# clients and J2EE on the server side with some major transaction happening. It will be another good journey.

Can't wait for Janeva version 2! Don't loose the marketing on this one Borland, I think you have hit something really good.

With Regards

James A Kirkup
Master IT Consulting
http://www.mitc.au.com