1. FreeBSD：
FreeBSD 是 FreeBSD 项目提供的免费开源操作系统。它是在两个类 Unix 操作系统 Berkeley Software Distribution (BSD) 和 Research Unix 的基础上设计的。它与 Linux 操作系统非常相似。它是早期著名的操作系统之一，但与其他操作系统相比，现在使用较少。 FreeBSD 的第一个版本于 1993 年推出。FreeBSD 的最新稳定版本是 12.1。
2. 索拉里斯：
Solaris 是由 Oracle Corporation 提供的专有操作系统。它是一个类 Unix 操作系统。它是用C语言和C++编写的。它有一个混合源模型，即开放和关闭源。它最初由 Sun Microsystems 开发，2010 年被 Oracle Corporation 收购。 Solaris 的第一个版本于 1992 年推出。该操作系统中使用的内核是具有可动态加载模块的 Monolithic。
Solaris 和 FreeBSD 的区别：
| Solaris | FreeBSD |
|---|---|
| It was developed by Sun Microsystems. | It was developed and is owned by The FreeBSD Project. |
| It was launched in 1992. | It was launched in 1993. |
| Its target system types are server and workstation. | Its target system type is server, workstation, NAS and embedded systems. |
| Computer architectures supported by Solaris are IA-32, x86-64 and SPARC. | Computer architectures supported are IA-32, x86-64, ARM, MIPS and PowerPC. |
| Its kernel type is Monolithic with dynamically loadable modules. | Kernel type is Monolithic with modules. |
| Its native APIs are SysV/POSIX, GTK and Java. | The native APIs are BSD/POSIX. |
| It has the preferred license of CDDL. | Preferred license is BSD. |
| Its package management is SysV packages or Image Packaging System. | Its package management is MSI. |
| File systems supported by Solaris are UFS, ZFS, ext2, FAT, ISO 9660, UDF, NFS and QFS. | File systems supported are UFS2, ZFS, ext2, ext3, FAT, ISO 9660, UDF and NFS. |