1. 艾克斯：
AIX 是 IBM 提供的一系列专有操作系统。 AIX 代表高级交互式执行程序。最初，它是为 IBM RT PC RISC 工作站设计的，后来它用于各种硬件平台，如 IBM RS/6000 系列、基于 PowerPC 的系统、System-370 大型机、PS-2 个人计算机和 Apple 网络服务器。它是通过 The Open Group 的 UNIX 03 标准认证的五个商业操作系统之一。 AIX 的第一个版本于 1986 年推出。AIX 的最新稳定版本是 7.2。
2. OpenVMS：
OpenVMS是由美国数字设备公司(DEC)开发的多用户多处理操作系统。它是一种基于虚拟内存的操作系统，设计用于分时、批处理和事务处理。它可用于许多平台，包括服务器和工作站。它是使用 BLISS、VAX Macro、C、Ada、PL/I、Fortran、UIL、Pascal、SDL、C++ 和 DCL 编写的。 OpenVMS 的第一个版本于 1977 年推出。该操作系统中使用的内核是带有模块的单体。
AIX 和 OpenVMS 的区别：
| AIX | OpenVMS |
|---|---|
| It was developed and is owned by IBM. | It was developed by Digital Equipment Corporation (DEC). |
| It was launched in 1986. | It was launched in 1977. |
| Its target system type is Server, NAS and workstation. | Its target system types are server and workstation. |
| Computer architectures supported are POWER, PowerPC-AS, PowerPC and Power ISA. | Computer architectures supported by OpenVMS are VAX, Alpha and IA-64. |
| Kernel type is Monolithic with modules. | Its kernel type is Monolithic with modules. |
| The native APIs are SysV/POSIX. | Its native APIs are Proprietary. |
| Preferred license is Proprietary. | It has the preferred license of Proprietary. |
| It has default GUI ‘on’. | It does not have default GUI ‘on’. |
| The non-native APIs supported through its subsystems are DOS API. | The non-native APIs supported through its subsystems are POSIX. |
| File systems supported are JFS, JFS2, ISO 9660, UDF, NFS, SMBFS and GPFS. | File systems supported by OpenVMS are Files-11, ISO 9660, NFS and CIFS. |