COSIX is a Chinese UNIX operating system developed since 1989 by China National Computer Software & Technology Service Corporation (CS&S). A jointly developed 64-bit version with Compaq was released in 1999.
An early version of the COSIX kernel was developed based on UNIX System V, and the 64-bit version was based on Tru64 UNIX. A Linux distribution named COSIX Linux was developed by CS&S and released in 1999, which had no technical relationship to COSIX.
References
COSIX Wikipedia(Text) CC BY-SA