1. 视窗：
Windows 是一组由 Microsoft Incorporation 提供的各种专有图形操作系统。它也被称为Microsoft Windows 。它目前包括 Windows NT 和 Windows IoT 作为其家族成员。早些时候，它包括不再使用的 Windows 9x、Windows Mobile 和 Windows Phone。它是个人计算机中最常用的操作系统。微软于 1985 年推出了 Windows 的第一个版本。它具有带有模块的混合内核。
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。
Windows 和 Plan 9 的区别：
| S.No. | WINDOWS | PLAN 9 |
|---|---|---|
| 1. | It was developed by Microsoft Incorporation. | It was developed by Bell Labs. |
| 2. | It was launched in 1985. | It was launched in 1993. |
| 3. | Its target systems types are workstation, personal computers, media center, tablets and embedded systems. | Its target system types are workstation, server, embedded and HPC. |
| 4. | Computer architectures supported by Windows are IA-32, x86-64, IA-64, ARM, Alpha, MIPS and PowerPC. | Computer architectures supported by Plan 9 are IA-32, Alpha, MIPS, PowerPC and SPARC. |
| 5. | Its kernel type is Hybrid with modules. | Its kernel type is Hybrid with user space like systems. |
| 6. | Its native APIs are Win32 and NT API. | Its native APIs are Proprietary (Unix-like). |
| 7. | It has the preferred license Proprietary and Source available. | It has the preferred license of LPL. |
| 8. | The non-native APIs supported through its subsystems are DOS API, Win16, POSIX and .NET. | The non-native APIs supported through its subsystems are POSIX compatibility layer. |
| 9. | Its package management is MSI or custom installer. | Its package management is none. |
| 10. | Its update management is Windows Update. | Its update management is replica. |
| 11. | File systems supported by Windows are NTFS, FAT, ISO 9660, UDF, HFS+, FATX and HFS. | File systems supported by Plan 9 are fossil/venti, 9P2000, kfs, ext2, FAT and ISO 9660. |