Comment Non-trivial was always cross-language (Score 1) 286
I get annoyed when the premise is so flawed, but stated as fact.
Major projects have been cross-language for decades. In the 70s, Fortran + C + Assembly were in most big languages. Or large systems using COBOL having to interface to non-COBOL systems. By the 80s, many had bits of Pascal (Borland was huge, remember?) and BASIC, with important routines hand-optimized in assembly. Or C. By the 90s, we had SQL and native code, DLLs written in random languages, and often VB for the UI. Most of what you use on a daily basis probably is browser-hosted but includes active controls in C# or C++, back end code in PHP or Java, database code in SQL and browser code in JavaScript or ActionScript. Many of my Android apps are mostly Java with some kernel-level support in C.
Yes, each language has it's own way... COM, exports, dllimport, etc. Until it has one, it's not a very functional language. But this isn't a new development.