What is the Major difference between Websphere Application Server v5.1, v6.1 and v7.0 ?

Profiles

WebSphere 5.1:No Concepts of profile ,there are 4 types of Installation -Express,Base ,Network Deployment and Enterprise.
Websphere 6.1:Cell Profile,Deployment Manager profile,Application Server profile,Custom Profile
Websphere 7.0 Cell(DeploymentManager and managed node),Management,Application Server,Custom profile,Secure Proxy.
Note:Under Management there are three types of profiles available :Administrative agent

Deployment Manager

Job Manager

Note:The Main use of Job Manager is to queue jobs to application server in a flexible management environment

Managing Profiles
WebSphere 5.1 :Websphere multiple installation instance can be created using wsinstance script

WebSphere 6.1:There are two ways of managing a profile
1.Profile Management Tool(GUI)

2.Manage profiles(Command interface for managing profiles )
WebSphere 7.0: same as 6.1

Security Roles
WAS 5.1:Administrator,operator,configurator
WAS 6.1:Administrator,operator,configurator,Deployer,Admin Security Manager,ISC Admin
WAS 7.0:Administrator,operator,configurator,Deployer,Admin Security Manager,ISC Admin,Auditor

WebServers supported
WAS 5.1:Apache HttpServer,Domino Server,IHS,Microsoft IIS,Sun Java System Web Server,HTTP Server for iseries
WAS 6.1:Apache HttpServer,Domino Server,IHS,Microsoft IIS,Sun Java System Web Server
WAS 7.0:HTTPServer for Z/Os and all web servers supported in 6.1

User Registries/Repositries
WAS 5.1:Local Operating System,Standalone LDAP registry,Standalone Custom registry
WAS 6.1:Federated repositories,Local Operating System,Standalone LDAP registry,Standalone Custom registry or file based registry
WAS 7.0:Same as 6.1

lOGGING AND TRACING
WAS 5.1Diagnostic trace
JVM logs
Process logs
IBM Service logs
WAS 6.1
Apart from the logs available in 5.1 there is a Change log detail levels which will enable the Message level and trace level of the JVM
WAS 7.0Same as V 6.1

Managing WebServers
WAS 5.1:Web Servers cannot be managed through Websphere Admin Console
WAS 6.1:WebServers can be Administered using the Websphere Admin Console (Stopping, Starting, Generation and propagation of Plug-in can be done). Web Servers can be created in Managed node or in Unmanaged node
WAS 7.0 same AS V 6.1

JMS
WAS 5.1:JMS Fail Over Support and scalability is not available
WAS 6.1:JMS Fail over support and scalability is available.SIB(Service Integration Bus Concept is being introduced)
WAS 7.0:Same as V 6.1

Monitoring
WAS 5.1:N/A
WAS 6.1:TPF(Tivoli Performance Viewer) is embedded in the Websphere Admin Console for monitoring WebSphere Objects
WAS 7.0same as V 6.1

Intelligent Run Time provisioning
WAS 5.1N/A
WAS 6.1N/A
WAS 7.0Intelligent run time provisioning is a new concept introduced in V7.0 At run time the server uses the activation plan to start only those components that are required inside the application server

Components like Web Container , EJB Container , Web Service and SIP Container are dynamically activated

SIP and Portlet Container
WAS 5.1:N/A
WAS 6.1SIP(Session Initiation Protocol) extends the application server to allow to run SIP applications written to JSR 116 Specification

The Portlet applications can deployed which is compliant with JSR 168

WAS 7.0same as V 6.1

wsadmin scripts
WAS 5.1:JACL is the scripting language which is used
WAS 6.1:JACL will be deprecated from 6.1 and Jython scripting will be used.
WAS 7.0:Same as V 6.1