content/markdown/what-is-maven.md

## Introduction

Maven, a [Yiddish word](https://en.wikipedia.org/wiki/Maven) meaning
*accumulator of knowledge*, was originally started as an attempt to
simplify the build processes in the Jakarta Turbine project. There were
several projects each with their own Ant build files that were all
slightly different and JARs were checked into CVS. We wanted a standard
way to build the projects, a clear definition of what the project
consisted of, an easy way to publish project information and a way to
share JARs across several projects.

The result is a tool that can now be used for building and managing any
Java-based project. We hope that we have created something that will
make the day-to-day work of Java developers easier and generally help
with the comprehension of any Java-based project.

## Maven's Objectives

Maven's primary goal is to allow a developer to comprehend the complete
state of a development effort in the shortest period of time. In order
to attain this goal there are several areas of concern that Maven
attempts to deal with:

-   Making the build process easy
-   Providing a uniform build system
-   Providing quality project information
-   Providing guidelines for best practices development
-   Allowing transparent migration to new features

### Making the build process easy

While using Maven doesn't eliminate the need to know about the
underlying mechanisms, Maven does provide a lot of shielding from the
details.

### Providing a uniform build system

Maven allows a project to build using its project object model (POM) and
a set of plugins that are shared by all projects using Maven, providing
a uniform build system. Once you familiarize yourself with how one Maven
project builds you automatically know how all Maven projects build
saving you immense amounts of time when trying to navigate many
projects.

### Providing quality project information

Maven provides plenty of useful project information that is in part
taken from your POM and in part generated from your project's sources.
For example, Maven can provide:

-   Change log document created directly from source control
-   Cross referenced sources
-   Mailing lists
-   Dependency list
-   Unit test reports including coverage

As Maven improves the information set provided will improve, all of
which will be transparent to users of Maven.

Other products can also provide Maven plugins to allow their set of
project information alongside some of the standard information given by
Maven, all still based on the POM.

### Providing guidelines for best practices development

Maven aims to gather current principles for best practices development,
and make it easy to guide a project in that direction.

For example, specification, execution, and reporting of unit tests are
part of the normal build cycle using Maven. Current unit testing best
practices were used as guidelines:

-   Keeping your test source code in a separate, but parallel source
    tree
-   Using test case naming conventions to locate and execute tests
-   Have test cases setup their environment and don't rely on
    customizing the build for test preparation.

Maven also aims to assist in project workflow such as release management
and issue tracking.

Maven also suggests some guidelines on how to layout your project's
directory structure so that once you learn the layout you can easily
navigate any other project that uses Maven and the same defaults.

### Allowing transparent migration to new features

Maven provides an easy way for Maven clients to update their
installations so that they can take advantage of any changes that been
made to Maven itself.

Installation of new or updated plugins from third parties or Maven
itself has been made trivial for this reason.

## What is Maven Not?

You may have heard some of the following things about Maven:

-   Maven is a site and documentation tool
-   Maven extends Ant to let you download dependencies
-   Maven is a set of reusable Ant scriptlets

While Maven does these things, as you can read above in the "What is
Maven?" section, these are not the only features Maven has, and its
objectives are quite different.

Maven does encourage best practices, but we realise that some projects
may not fit with these ideals for historical reasons. While Maven is
designed to be flexible, to an extent, in these situations and to the
needs of different projects, it can not cater to every situation without
making compromises to the integrity of its objectives.

If you decide to use Maven, and have an unusual build structure that you
cannot reorganise, you may have to forget some features or the use of
Maven altogether.