is compiler 10 backward compatible with 9?

[abhimodak]

Sorry for asking this a bit dumb question...but we have customers that want an authoritative answer to it. The need arises due to supporint user-defined function i.e.API support. Is there any particular document that I can refer to that can address most of it, if not all?

Abhi

[Steven_L_Intel1]

It depends on what you mean by "backward compatible". So here are some possibilities and answers.

Can I compile with version 9 and link with version 10? Yes.
Can I compile with version 10 and link with version 9? No.
Will source that compiles with version 9 compile with version 10? Yes, if it is correct.
Will source that compiles with version 10 compile with version 9? No if you used any new language features.

If you are building a library that is to be used by version 9 customers, then you must build this library with version 9. That library can also be used with version 10 (with minor exceptions described in the release notes, mainly related to module variables.)

If this does not answer your question, please elaborate and I'll be glad to do likewise.

[wolfgang_trautenberg]

May objects compiled with 9.1 be mixed with objects compiled with ifort 10.1
when linked with 10.1 and 10.1 libraries? (Windows)

[Steven_L_Intel1]

Yes, with minor exceptions as noted in the release notes.