We want to create a system/application with several coverages (i.e inventory, monitoring, etc). But me and my friend knows different programming languages. I know java and he knows vb.net but neither of us knows both. In any case, is it possible if java can work with vb.net? for example, the inventory part will be develop using java and the monitoring part will be created using vb.net. If so, is there a disadvantage in doing such thing?
Thank you :)
An alternative to Bathsheba's answer is separating the program not by functions but by tiers. Create a server with the bussiness logic in Java, a frontend with C#, communicated by a standard (SOAP, JSON, RESTful, whatever).
Of course, a tiered system involves a little more effort than an desktop application connecting to ODBC, but also solves many trouble that you have still not thought about (scalability, authentication, security...).
Anyway, making half the product in a language and half in another will be ugly and will difficult maintenance (because there will be a need to keep a C# programmer and a Java programmer). It would be better if you both switched to one language (the expert to the chosen language would program the core logic, while the newbie would design the webpages with ASP/JSP).