In collaborative projects with source files being edited on a variety of platforms, editors, and locales, encoding issues can become a real PITA.
In such setting, it is best to define one "right", mandatory encoding (UTF-8), communicate this clearly and stick to it. However, in many cases the collaborators, especially if they stem from the Windows or Mac world, do not even know what an encoding is. What, however, works reasonably well in practice, is the following.
Prepare templates that already are in the right encoding, including (if appropriate) the \usepackage[utf8]{inputenc} line. The template also should (at least in some comment), contain some UTF-8 characters: Many modern editors have reasonably good heuristics to detect the encoding "automagically" if non-ASCII characters are present.
Provide editor modelines for as many editors as possible. Many editors, including WinEdt and TeXShop, provide a modeline syntax that can also be used to specify the encoding explicitly. Many other support either the vim or emacs modeline syntax, so those should always be present. But of course, there are more.
The following document header includes some UTF-8 characters and modeline commands to set the file type (for syntax coloring) to TeX/LaTeX and the encoding to UTF-8 for: vim, WinEdt, TexShop, Emacs, and Kate:
% vim: set fenc=utf-8 ft=latex
% !Mode:: "TeX::UTF-8"
% !TEX encoding = UTF-8 Unicode
% -*- mode: latex; coding: UTF-8; -*-
% kate: encoding utf-8;
%
% IMPORTANT Note: This file is UTF-8 encoded!
% You should see some umlauts here: ÄÖÜäöü
The Kate modeline might also work for Texmaker, as both are based on the generic Qt editor component, but I have not checked this. For most editors, modelines have to appear in the first 10 lines of a document, some (Vim, Emacs) also support them at the end of the document (within the last 10 lines).
\usepackage[latin1]{inputenc}in it is sufficient. – egreg Jan 8 at 13:40inputencloaded, as you wrote. Can I copy some parts and paste to my file and edit and compile on my Linux? Or your comments only works to compile each file separately? – Sigur Jan 8 at 13:44\inputencoding{latin1}\input{fileinlatin1}\inputencoding{utf8}. But working with multiple encodings is better avoided. – egreg Jan 8 at 13:57