[N3WBI3]

But can a perl app on a UNIX server interact (two-way) with a COBOL or RPG app on an OS/400 server without going through an Application Server constructed to handle the interaction?

So long as the app has an API interface, yes it can..

Can a Java app on a UNIX server interact (two way) with an SPSS app on a mainframe?

Yes infact we do some of that at my shop, our Java guys are pretty sharp. There is a company called openconnedt that sells such products as well.

Can a php app on a UNIX server call any procedural code (RPG, COBOL, etc.) on a second, remote server (other than the one on which the php app is installed) in which Java is not enabled?

Yes so long as the other serve is listening for it, mind you directly calling is an aweful idea and leads to security mess later down the road..

[StJacques]

"So long as the app has an API interface, yes it can.."

An API interface? Aren't you referring to an "Application Server" here, which would provide the "API interface"? Like Kerberos or one of Vintela's products? (Or a custom-built one specifically designed for the purpose.)

"Yes infact we do some of that at my shop, our Java guys are pretty sharp. There is a company called openconnedt that sells such products as well."

Are you telling me your Java guys are doing this without one of those third-party products, i.e. "Application Servers," or an interface constructed for handling the communication placed on the mainframe? Note: Sun Microsystems will tell you that application servers are needed to form a bridge between Java apps and other apps written and installed in non-object-oriented programming languages.

"Yes so long as the other server is listening for it, mind you directly calling is an aweful idea and leads to security mess later down the road.."

The phrase "so long as the other server is listening for it" makes clear that an interface must be constructed to handle the communication. .NET apps do not require such an interface.

The problem you cannot get away from here is that something must be either installed to form a bridge between applications of differing types installed on UNIX and servers running distinct operating systems or an interface must be specially constructed to handle the interaction. That cross-platform interoperability is not available on a continuous basis to enable apps installed on UNIX servers to communicate with other apps of differing types installed on servers running different operating systems. In .NET no additional installations are required. You are cross-platform enabled from the git-go.