JSR is a "Java Specification Request". Liferay Portal is developed to ADHERE to JSR 168 and JSR 286 specifications. 

This specification is created by committee of JEE portal vendors. This specification is designed to achieve INTEROPERABILITY between different portals and portlets.

Liferay supports mainly below JSRs: 

JSR-168(Portlet 1.0) 
JSR-286(Portlet 2.0) 
JSR-127(JSF 1.0) 
JSR-170 
JSR-314(JSF 2.0) 
JSR-329

Why these standards are defined?

These standards are defined for the benefit of portal users (end customers). Before these standards were born, portal customer were required to use one portal and there was no easy way to switch between different portal vendors. Earlier portal were very vendor specific and all functionality were developed using PROPRIETARY API, technology and programming techniques. The JSR 168 and JSR 286 standards have defined the way portlets can be developed that will help users in long RUN. 

Benefits of Following JSR Standards:

Following these standards will ensure that there is no vendor lock in. However this can be guaranteed only when the portlets are developed sticking to the standards.

JSR is a "Java Specification Request". Liferay Portal is developed to adhere to JSR 168 and JSR 286 specifications. 

This specification is created by committee of JEE portal vendors. This specification is designed to achieve interoperability between different portals and portlets.

Liferay supports mainly below JSRs: 

JSR-168(Portlet 1.0) 
JSR-286(Portlet 2.0) 
JSR-127(JSF 1.0) 
JSR-170 
JSR-314(JSF 2.0) 
JSR-329

Why these standards are defined?

These standards are defined for the benefit of portal users (end customers). Before these standards were born, portal customer were required to use one portal and there was no easy way to switch between different portal vendors. Earlier portal were very vendor specific and all functionality were developed using proprietary API, technology and programming techniques. The JSR 168 and JSR 286 standards have defined the way portlets can be developed that will help users in long run. 

Benefits of Following JSR Standards:

Following these standards will ensure that there is no vendor lock in. However this can be guaranteed only when the portlets are developed sticking to the standards.