One of the problems with writing non-English documents in LATEX is
the accent commands. Reading documents containing text like
na\"\i ve is frustrating, especially if your keyboard allows
you to type naïve.
In the past, LATEX has not supported input containing accented characters such as ï, because Windows, Macintosh and Unix all have different ways of dealing with accented input, called input encodings.
However, the inputenc package allows you to specify which input
encoding your document is written with, for example to use the ISO
Latin-1 encoding, you type:
\usepackage[latin1]{inputenc}
At the moment, inputenc supports the ascii and
latin1 input encodings, but more will be added with future
releases.
The inputenc package is
currently a test release. The user interface for the full release will
be upwardly compatible with the test version.