X/Open是1984年由多个公司联合创建的一个用于定义和推进信息技术领域开放标准的公司，X/Open和开放软件基金会合并为The Open Group，并在1993-1996管理UNIX这个商标。

X/Open Company, Ltd., originally the Open Group for Unix Systems, was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of information technology. More specifically, the original aim was to define a single specification for operating systems derived from UNIX, to increase the interoperability of applications and reduce the cost of porting software. Its original members were Bull, ICL, Siemens, Olivetti, and Nixdorf—a group sometimes referred to as BISON. Philips and Ericsson joined soon afterwards, at which point the name X/Open was adopted.