Dear All,
I am going to design an architect which is mainly .Net frontend(VB .Net) and Java backend.
In interoperating between .Net and Java, below are some choices
Synchronous
1. Synchronous Web Service
2. Remoting
3. HTML/HTTP (such as HTTP POST calls)

Asynchronous
1. Asynchronous Web Service
2. Messaging

In considering there might be Java client in the future and performance and scability are critical for this project(there might be thousands of concurrent users). Which techolologies would you use and why? On the other hand, in considering ease of development and maintenance, what would you choose?