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，后来它被用于各种硬件平台，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. 方案九：
Plan 9 是由贝尔实验室开发的分布式操作系统。它是在贝尔实验室的计算机科学研究中心 (CSRC) 创建的。它是一个免费的操作系统。它是用ANSI C的方言编写的。它的目标系统是工作站、服务器、嵌入式系统和HPC。它是一个类 Unix 操作系统。它是一个开源操作系统。 Plan 9 的第一个版本于 1993 年推出。其内核类型与用户空间文件系统混合。
AIX 和 Plan 9 的区别：
| AIX | Plan 9 |
|---|---|
| It was developed and is owned by IBM. | It was developed by Bell Labs. |
| It was launched in 1986. | It was launched in 1993. |
| Its target system type is Server, NAS and workstation. | Its target system types are workstation, server, embedded and HPC. |
| Computer architectures supported are POWER, PowerPC-AS, PowerPC and Power ISA. | Computer architectures supported by Plan 9 are IA-32, Alpha, MIPS, PowerPC and SPARC. |
| Kernel type is Monolithic with modules. | Its kernel type is Hybrid with user space like systems. |
| The native APIs are SysV/POSIX. | Its native APIs are Proprietary (Unix-like). |
| Preferred license is Proprietary. | It has the preferred license of LPL. |
| Its package management depends on the distribution. | Its package management is none. |
| Update management is Service Update Management Assistant (SUMA). | Its update management is replica. |
| File systems supported are JFS, JFS2, ISO 9660, UDF, NFS, SMBFS and GPFS. | File systems supported by Plan 9 are fossil/venti, 9P2000, kfs, ext2, FAT and ISO 9660. |