Many customers rely on the Solaris operating environment as the foundation for mission critical applications. UNIX 98 branding shows Sun's continuing involvement in providing a stable operating environmnet.
Interfaces previously defined in the ISO POSIX-2 standard, C language binding, shared memory, enhanced internationalization, and the transfer of the X/Open UNIX Extension Freature Groups into the BASE
The addition of threads and a Realtime Threads Feature Group to align with POSIX
Multibyte extension (MSE) to align with the ISO/IEC
Large file summit (LFS) extensions for support of 64-bit or larger files and filesystems
X/Open-specific threads extensions and dynamic linking
Year 2000 compliance