What technology is needed to start developing?

What all technology I need to learn to get started contributing ?

@Mohit, technologies needed for OpenMRS the following list is the most needed: 1.) Git and GitHub - for software configuration and management. 2.) JIRA - for issue tracking 3.) IDE - for development (i.e., NetBeans, Eclipse, or IntelliJ IDEA) and Maven 4.) FrontEnd development (The User Interface - Presentation Layer): 4.1.) JSP, HTML5, or AngularJS 4.2.) JavaScript 4.3.) Spring MVC 4.4.) Groovy, JQuery 5.) BackEnd Development (The Service Layer and The Data Access Layer) 5.1.) Spring Framework (AOP and DI) 5.2.) Hibernate - for Data Modeling

For compete information please refer to the link: http://devmanual.openmrs.org/en/

Good luck