For years, it seems forever, noone had to question about binary compatibility for Solaris applications. They would just run.

For years, AIX support and sales asked IBM to guarantee, in writing, what was pretty much standard practice. And in 2007, with the arrival of AIX 6.1 - binary compatibility was guaranteed. And this guarantee was extended from AIX 6.1 into AIX 7.1. The clue: use shared libraries and API's. The new shared libraries do the work, should it be necessary, to make it work.

Now it seems AIX stands alone.

Oracle's message (technical whitepaper) to ISVs!

In a document published by Oracle entitled: Oracle Solaris 11 ISV Adoption Guide the Executive Overview says, simply - Q. quaranteed? A. not any longer:

This document is designed to help independent software vendors (ISVs) transition their
applications smoothly from Oracle Solaris 10 to Oracle Solaris 11. It provides a list of all
currently known modifications, which may be needed for existing applications to run on Oracle
Solaris 11. The majority of applications will work without any modification. However, applications that rely on outdated frameworks and undocumented APIs may require minor changes.