# Installing and Testing MathJax¶

The easiest way to use MathJax is to link directly to the MathJax
distributed network service (see *Using the MathJax CDN*). In that case, there is no need to install MathJax
yourself, and you can begin using MathJax right away; skip this document on
installation and go directly to *Configuring MathJax*.

MathJax can be loaded from a public web server or privately from your hard drive
or other local media. To use MathJax in either way, you will need to obtain a
copy of MathJax and its font package. There are three ways to do this: via
`git`, `svn`, or via a pre-packaged archive. We recommend git or svn, as it
is easier to keep your installation up to date with these tools.

## Obtaining MathJax via Git¶

The easiest way to get MathJax and keep it up to date is to use the Git version control system to access our GitHub repository. Use the command

```
git clone git://github.com/mathjax/MathJax.git MathJax
```

to obtain and set up a copy of MathJax. Note that there is no longer
a `fonts.zip` file, and that the `fonts` directory is now part of
the repository itself.

Whenever you want to update MathJax, you can now use

```
cd MathJax
git remote show origin
```

to check if there are updates to MathJax (this will print several lines of data, but the last line should tell you if your copy is up to date or out of date). If MathJax needs updating, use

```
cd MathJax
git pull origin
```

to update your copy of MathJax to the current release version. If you keep MathJax updated in this way, you will be sure that you have the latest bug fixes and new features as they become available.

This gets you the current development copy of MathJax, which is the version that contains all the latest changes to MathJax. Although we try to make sure this version is a stable and usable version of MathJax, it is under active development, and at times it may be less stable than the “release” version. If you prefer to use the most stable version (that may not include all the latest patches and features), you will want to get one of the tagged releases. Use

```
cd MathJax
git tag -l
```

to see all tagged versions, and use

```
cd MathJax
git checkout <tag_name>
```

to checkout the indicated version of MathJax, where `<tag_name>` is
the name of the tagged version you want to use. When you want to
upgrade to a new release, you will need to repeat this for the latest
release tag.

Each of the main releases also has a branch in which critical updates are applied (we try hard not to patch the stable releases, but sometimes there is a crucial change that needs to be made). If you want to use the patched version of a release, then check out the branch rather than the tag. Use

```
cd MathJax
git branch
```

to get a list of the available branches. There are separate branches
for the main releases, but with `-latest` appended. These contain
all the patches for that particular release. You can check out one of
the branches just as you would a tagged copy. For example, the branch
for the `v1.1` tagged release is `v1.1-latest`. To get this
release, use

```
cd MathJax
git checkout v1.1-latest
```

and to update it when changes occur, use

```
cd MathJax
git pull origin v1.1-latest
```

## Obtaining MathJax via SVN¶

If you are more comfortable with the subversion source control system, you may want
to use GitHub’s `svn` service to obtain MathJax. If you want to get the
latest revision using `svn`, use the command

```
svn checkout http://svn.github.com/mathjax/MathJax.git MathJax
```

to obtain and set up a copy of MathJax. Note that there is no longer
a `fonts.zip` file, and that the `fonts` directory is now part of
the repository itself.

Whenever you want to update MathJax, you can now use

```
cd MathJax
svn status -u
```

to check if there are updates to MathJax. If MathJax needs updating, use

```
cd MathJax
svn update
```

to update your copy of MathJax to the current release version. If you keep MathJax updated in this way, you will be sure that you have the latest bug fixes and new features as they become available.

This gets you the current development copy of MathJax, which is the version
that contains all the latest changes to MathJax. Although we try to make
sure this version is a stable and usable version of MathJax, it is under
active development, and at times it may be less stable than the “release”
version. If you prefer to use one of the tagged releases instead, then
either use `git` as described above, or one of the archive files as
described below. You can use

```
svn checkout http://svn.github.com/mathjax/MathJax.git@nnn mathjax
```

to check out revision number nnn, but it is not easy to tell what
svn revision number is associated with a particular release. GitHub’s
`svn` service doesn’t appear to allow you to specify a particular
tagged version.

## Obtaining MathJax via an archive¶

Release versions of MathJax are available in archive files from the MathJax download page or the GitHub downloads (click the big download button on the right), where you can download the archive that you need.

You should download the v1.1 archive (which will get you a file with a
name like `mathjax-MathJax-v1.1-X-XXXXXXXX.zip`, where the X’s are
some sequence of random-looking letters and numbers), then simply unzip
it. Once the MathJax directory is unpacked, you should move it to the
desired location on your server (or your hard disk, if you are using
it locally rather then through a web server). One natural location is
to put it at the top level of your web server’s hierarchy. That would
let you refer to the main MathJax file as `/MathJax/MathJax.js` from
within any page on your server.

From the MathJax GitHub download link (the download button at the
right), you can also select the `Download .tar.gz` or `Download
.zip` buttons to get a copy of the current development version of
MathJax that contains all the latest changes and bug-fixes. You can
also get older tagged versions (if there are any).

If a packaged release receives any important updates, then those
updates will be part of the branch for that version. The link to
the `.zip` file in the download list will be the original release
version, not the patched version. To obtain the patched version, use
the Branches drop down menu (at the far left of the menus within the
page) to select the release branch that you want (for example
`v1.1-latest`), and then use the download button and the `Download
.tar.gz` or `Download .zip` button to get the latest patched
version of that release.

## Testing your installation¶

Use the HTML files in the `test` directory to see if your
installation is working properly:

```
test/
index.html # Tests default configuration
index-images.html # Tests image-font fallback display
sample.html # Sample page with lots of pretty equations
```

Open these files in your browser to see that they appear to be working
properly. If you have installed MathJax on a server, use the web
address for those files rather than opening them locally. When you
view the `index.html` file, you should see (after a few moments) a
message that MathJax appears to be working. If not, you should check
that the files have been transferred to the server completely, and that
the permissions allow the server to access the files and folders that
are part of the MathJax directory (be sure to verify the MathJax
folder’s permissions as well). Checking the server logs may help
locate problems with the installation.

## Firefox and local fonts¶

Firefox’s same-origin security policy affects its ability to load
web-based fonts, as described above. This has implications not only
to cross-domain loading of MathJax, but also to using MathJax locally
from your hard disk. Firefox’s interpretation of the same-origin
policy for local files is that the “same domain” for a page is the
directory where that page exists, or any of its subdirectories. So if
you use MathJax in a page with a `file://` URL, and if MathJax is
loaded from a directory other than the one containing the original
page, then MathJax will not be able to access the web-based fonts in
Firefox. In that case, MathJax will fall back on image fonts to
display the mathematics.

In order for Firefox to be able to load the fonts properly for a local file, your MathJax installation must be in a subdirectory of the one containing the page that uses MathJax. This is an unfortunate restriction, but it is a limitiation imposed by Firefox’s security model that MathJax can not circumvent. Currently, this is not a problem for other browsers.

One solution to this problem is to install the MathJax fonts locally, so
that Firefox will not have to use web-based fonts in the first place. To
do that, either install the STIX fonts, or copy
the fonts from `MathJax/fonts/HTML-CSS/TeX/otf` into your systems fonts
directory and restart your browser (see the MathJax fonts help page for details).

## IE9 and remote fonts¶

IE9’s same-origin policy affects its ability to load web-based fonts, as
described above. This has implications not ony to cross-domain loading of
MathJax, but also to the case where you view a local page (with a
`file://` URL) that accesses MathJax from a remote site, like the MathJax
CDN service. In this case, IE9 does **not** honor the
`Access-Control-Allow-Origin` setting of the remote server (as it would
if the web page came from an `http://` URL), and so it **never** allows the
font to be accessed.

One solution to this problem is to install the MathJax fonts locally so that MathJax doesn’t have to use web-based fonts in the first place. Your best bet is to install the STIX fonts on your system (see the MathJax fonts help page for details).