Intended audience. This document is intended for system administrators that want to upgrade an existing Liferay Portal installation to a new version and developers that have done developments for a given version and want them to work in a later version.

Liferay version. This guide has been written for Liferay 4.2. It includes information for upgrading from 4.1 and some previous versions.

Related documents. If this is not what you are looking for consider the following related documents:

More information and support. If you have are looking for help in an specific issue we invite you to use our community forums: http://www.liferay.com/web/guest/devzone/forums to explain your problems and ask your questions. We also offer professional support services (support@liferay.com)where your company can be assigned a Liferay developer that will ensure that your questions are answered promptly so that your project is never compromised. Purchased support always gets first priority. This business model allows us to build a company that can contribute a great portal to the open source community. If your company uses Liferay, please consider purchasing support. Liferay has an extremely liberal license model (MIT, very similar to Apache and BSD), which means you can rebundle Liferay, rename it, and sell it under your name. We believe free means you can do whatever you want with it. Our only source of revenue is from professional support and consulting.

	Note
	This guide is a work in progress in its early stages