The SIL Arabic script fonts are encoded according to Unicode, so your application must support Unicode text in order to access letters other than the standard ANSI characters. Most applications now provide basic Unicode support. You will, however, need some way of entering Unicode text into your document.
The Arabic script font packages do not include any keyboarding helps or utilities. If you cannot use the built-in keyboards of the operating system, you will need to install the appropriate keyboard and input method for the characters of the language you wish to use. If you want to enter characters that are not supported by any system keyboard, the Keyman program can be helpful on Windows, macOS, Linux, Android and iOS systems. Also available for Windows is MSKLC. For other platforms, XKB or Ukelele can be helpful.
If you want to enter characters that are not supported by any system keyboard, and to access the full Unicode range, we suggest you use gucharmap, kcharselect on Ubuntu or similar software. Another method of entering some symbols is provided by a few applications such as Adobe InDesign. They can display a glyph palette that shows all the glyphs (symbols) in a font and allow you to enter them by clicking on the glyph you want.
Other suggestions are listed here: Keyboard Systems Overview.
SIL’s Arabic script fonts are designed to work with two advanced font technologies, Graphite and OpenType. To take advantage of the advanced typographic capabilities of these fonts, you must be using applications that provide an adequate level of support for Graphite or OpenType.
Other suggestions are listed here: Applications Support.
One common type of data conversion is from Roman script to Arabic script. Cross-script conversion is often very language specific. TECkit is one program that can be used for character encoding conversion. TECkit allows users to write their own custom conversion mappings. The TECkit package is available for download from SIL’s TECkit Web site. The SIL Converters software will be an important tool in data conversion.
One page that may prove helpful is: Roman Script to Arabic Script Conversion.
Other suggestions are listed here: Introduction to Text Conversion and Transliteration.