The **PacletInfo.m** is a descriptor file for
*Mathematica* applications. In the current
version of *Mathematica* it is only used by the
documentation system. This means that if you provide
documentation for your application you must provide a
**PacletInfo.m**, and *Mathematica* will
locate your documentation based on its settings.
Other contents of the application, such as *Mathematica* code, are
found by installing the application on the *Mathematica*
**$Path**.

A sample **PacletInfo.m** is shown in the following.

The **PacletInfo.m** contains a set of rules that describe
the application and what it contains. You can see details
in the contents section.

The paclet system lets you install more than one application of the same
name, so long as the **PacletInfo.m** have different version numbers.
When selecting which one to use, it looks at all that are suitable
for that version of *Mathematica* and picks the one with the
highest version number.

The Wolfram *Workbench* provides a special multi-page editor for the
**PacletInfo.m** that helps you to work with it. When
you open the file you see an overview page, with tabs
to navigate to the other pages. An example is shown below.

If you change anything in these fields, you will need to save the editor.

You can visit the other pages of the editor by clicking on the respective tabs.

The **Extensions** tab lists all the extensions in the **PacletInfo.m**.
Typically, this is just going to list the **Documentation** extension.
A sample follows.

The details of this tab are described in the section on the documentation extension.

The **Documentation** tab shows the documentation you have
written for your application. An example is shown below.

From this page you add or remove documentation pages. There are also special tools for creating symbol pages and an overview page.

The **PacletInfo.m** tab shows the raw source of the file. You can
edit the contents of the file directly, but typically this is not necessary
since the other tabs provide a way to set it up.