1. Linux：
Linux 是一组开源的类 Unix 操作系统，由 Linus Torvalds 开发。它是一个打包的 Linux 发行版。一些最常用的 Linux 发行版是 Debian、Fedora 和 Ubuntu。它基本上是用C语言和汇编语言编写的。 Linux 中使用的内核是 Monolithic 内核。 Linux 发行版的目标系统是云计算、嵌入式系统、移动设备、个人计算机、服务器、大型计算机和超级计算机。 Linux 的第一个版本于 1991 年推出。
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。
Linux 和 Plan 9 的区别：
| S.No. | LINUX | PLAN 9 |
|---|---|---|
| 1. | It was developed by Linus Torvalds. | It was developed by Bell Labs. |
| 2. | It was launched in 1991. | It was launched in 1993. |
| 3. | Its target system types are embedded systems, mobile devices, personal computers, servers, mainframe computers and supercomputers. | Its target system types are workstation, server, embedded and HPC. |
| 4. | Computer architectures supported by Linux are IA-32, x86-64, ARM, PowerPC and SPARC. | Computer architectures supported by Plan 9 are IA-32, Alpha, MIPS, PowerPC and SPARC. |
| 5. | Its kernel type is Monolithic. | Its kernel type is Hybrid with user space like systems. |
| 6. | Its native APIs are LINUX/POSIX. | Its native APIs are Proprietary (Unix-like). |
| 7. | It has preferred license of GNU GPLv2 (kernel). | It has the preferred license of LPL. |
| 8. | The non-native APIs supported through its subsystems are Mono, Java, Win16 and Win32. | The non-native APIs supported through its subsystems are POSIX compatibility layer. |
| 9. | Its package management depends on the distribution. | Its package management is none. |
| 10. | Its update management depends on the distribution. | Its update management is replica. |
| 11. | File systems supported by Linux are ext2, ext3, ext4, btrfs, ReiserFS, FAT, ISO 9660, UDF and NFS. | File systems supported by Plan 9 are fossil/venti, 9P2000, kfs, ext2, FAT and ISO 9660. |