Windows Interface Source Environment (or WISE) was a licensing program from Microsoft which allowed developers to recompile and run Windows-based applications on UNIX and Macintosh platforms.
[1] WISE SDKs were based on an emulation of the Windows API which could run on Unix and Macintosh platforms.
Instead, Microsoft established partnerships with several software providers (which needed to have access to Windows internals source code), which in turn sold WISE SDKs to end-users.
[3] Companies which provided WISE SDKs needed to have access to Windows source code, which made them dependent on Microsoft's good will.
[7] To be able to develop WISE SDKs, software providers needed to have access to Windows internals source code.