Managing Your Computing Environment
You can optimize Mathematica for systems with small screens using any or all of the following methods.
Change the magnification of notebooks by using Format Magnification.
Set the screen environment to a condensed layout through the Format Screen Style Environment submenu.
Close any notebooks not in use.
Close any palettes not in use.
Resize the Help Browser.
When using keyboard shortcuts for menu commands, certain alternates have been established based on U. S. keyboards. For instance,  is an alternative for [^] since both characters are located on the same key on U.S. keyboards.
In the case of international keyboards, some keyboard shortcuts may not work, such as shortcuts involving characters created using the German Alt+GR key. For most shortcuts, there are alternatives that should always work.
Notebook files have the default extension .nb. The notebook is stored in 7-bit ASCII. The file can use either CR, LF, or CR/LF newlines. Notebooks are platform independent, so they can be used unchanged on any computer system that supports Mathematica.
Sharing Notebooks with others
Because notebooks contain only printable ASCII characters, notebooks can be sent directly by email or transferred by FTP in text mode. For colleagues without Mathematica, MathReader is a free read-only viewer for notebooks. It is available to download at www.wolfram.com/products/mathreader.
Notebooks on the web
Notebooks can be saved as HTML or XML files (see Importing and Exporting). Mathematica notebooks can also be made available through the web. Most web browsers can be configured to indicate that any file with the extension .nb should be viewed with Mathematica.
Use the following settings to register Mathematica as a helper application in your web browser.
MIME type: application/mathematica
File type: text
Action: launch application
With these settings, downloaded notebooks will automatically be opened with Mathematica.
See www.wolfram.com/webmathematica for the latest information on using Mathematica with the web.
To reduce memory use in the front end:
Close notebooks when you are finished with them.
Clear the Clipboard by copying something small to replace large data. Or, use Edit Paste As Paste and Discard instead of Paste.
If you only need to edit a notebook, run the front end without starting the kernel.
Save notebooks after large results and plots.
To reduce memory use in the kernel:
Use a setting such as $HistoryLength=10 to limit the number of input and output lines stored.
Use Remove[vars] to remove any unnecessary variables.
Use the command Share periodically to share the storage of common subexpressions.
Mathematica comes equipped with hundreds of built-in functions. However, if you work in a specialized area, you may find that you need functions that are not built into Mathematica. You can extend Mathematica's capabilities beyond the built-in functions by using application packages. The standard application packages included with Mathematica are files written in the Mathematica language that add functions to the kernel. Standard packages are located in the directory $InstallationDirectory/AddOns/StandardPackages. To see the exact location for $InstallationDirectory, evaluate the command $InstallationDirectory in a notebook.
Application packages that are not part of a Mathematica distribution are typically installed in $BaseDirectory. Application packages installed in $BaseDirectory will be available to all users. Application packages intended for a particular user are located in the user-specific directory specified by $UserBaseDirectory. To see the exact location for either of these directories, evaluate the command $BaseDirectory or $UserBaseDirectory in a notebook.
Application packages can be installed in either the Applications or Autoload subdirectories of $BaseDirectory or $UserBaseDirectory. Application packages installed in the Autoload subdirectory are automatically loaded when you start Mathematica. Applications installed in the Applications subdirectory can be loaded manually using the Needs or Get(<<) commands.
For more information on packages and loading, see The Mathematica Book, Section 1.3.10, or go to Add-ons & Links Working with Add-ons in the Help Browser.
J/Link is a toolkit that integrates Mathematica and Java. Mathematica can call Java in a completely transparent way, and Java programs can call Mathematica using a very high-level interface. More information on J/Link is available in the Help Browser under Add-ons & Links J/Link.
MathLink is an open interprocess communication protocol that allows external programs to call Mathematica or be called by Mathematica. Included on the CD-ROM under AddOns are compressed sample projects demonstrating how to use MathLink with several popular compilers.
More information on MathLink is available in The Mathematica Book, Sections 1.11.11 and 2.13, in the Help Browser under Add-ons & Links MathLink, and on the web at www.wolfram.com/solutions/mathlink.
.NET/Link is a toolkit that integrates Mathematica and Microsoft's .NET Framework. Mathematica can call .NET programs written in any language in a completely transparent way, and .NET programs can call Mathematica using a very high-level interface. On machines running Microsoft Windows, more information on .NET/Link is available in the Help Browser under Add-ons & Links .NET/Link.