RHEL5的版本主要分为Sever和Desktop两个版本。

具体来说，Server版本分为：
· Red Hat Enterprise Linux Advanced Platform - 对应以前的· Red Hat Enterprise Linux AS
· Red Hat Enterprise Linux - 对应以前的Red Hat Enterprise Linux AS
Desktop版本分为：
· Red Hat Enterprise Linux Desktop - 对应以前的Red Hat Desktop
· Red Hat Enterprise Linux Desktop with Workstation option - 对应以前的Red Hat Enterprise Linux WS

主要的功能包括：

1. 虚拟化技术
在各种平台上支持虚拟化技术
在Red Hat Enterprise Linux Advanced Platform支持存储与扩展的服务器虚拟化技术
Red Hat Network提供各种虚拟化系统的支持
virt-manager, libvirt/virsh管理工具

2. 内核与性能
基于Linux 2.6.18内核
支持多核处理器
广泛的新硬件支持
更新的基于Kexec/Kdump的Dump支持
支持Intel Network Accelerator Technology (IOAT)
对于大型SMP系统技持的增强
增强的管道缓存
内核缓存接合能力用于改进IO缓存操作

3. 安全
SELinux增强
图形化SELinux管理界面
集成的目录和安全机制
增强的IPESEC提高安全与性能
新的审计机制用于提供新的搜索、报表和实时监控的能力

4. 网络与互操作性
支持Autofs, FS-Cache和iSCSI
增强的IPv6支持
改进的Microsoft®文件/打印和Active Directory集成

5. 桌面
更新的管理工具、应用程序和对笔记本的支持
改进的ACPI支持，包括Suspend to Disk
智能卡登录，包括PKI/Kerberos认证
集成的多媒体支持
增强的即插即用支持
Network Manager提供自动的有线和无线网络配置
基于AIGLX/Compiz的图形化界面(支持淡化、透明等效果)

6. 开发环境
增强的开发工具，包括System Tap和Frysk
GCC4.1和glibc 2.5工具链

7. 存储
支持根设置多路IO(MPIO)，提高可用性
服务器产品中包含单系统/客户的Red Hat Global File System支持
块设备数据加密支持

8. 管理
安装过程更新简化系统配
基于Yum/Pup的Red Hat Network更新
Conga集群和存储管理

Red Hat Enterprise Linux 5 server

Introducing Red Hat Enterprise Linux Advanced Platform

Advanced technologies are now available to everyone. Better availability. Flexibility. Improved security and performance. 

Advanced Platform eliminates the cost and complexity of enterprise-class virtualization, high availability, and storage management software. These are included in the platform. Fully integrated and supported. Simple and afforable. 

The benefits of choosing Red Hat

A huge ecosystem of hardware and software partners, offering both services and certified solutions, makes Red Hat the industry leader. This powerful combination provides: 

-Thousands of certified applications from Independent Software Vendors (ISVs) 
-Hundreds of certified hardware systems and peripherals from leading OEM vendors, spanning multiple processor architectures 
-A range of partner programs 
-Comprehensive service offerings, up to 24x7 support with 1-hour response, available from Red Hat and selected ISV/OEM partners 
-Excellent performance, security, scalability, and availability, with audited industry benchmarks
-Open source technologies rigorously tested and matured through the Red Hat sponsored Fedora project 
-With each major version, stable application interfaces and 7 years of product support 
-A homogeneous client/server product family that enables seamless inter-operation of systems from the laptop to the data-center to the mainframe. Plus, excellent interoperability with existing Unix and Microsoft® Windows® deployments