Quest's interface can be customised by creating LDFs - Language Definition Files. These files hold all the text for Quest's menus, windows etc. To translate the interface, create a copy of ENGLISH.LDF, and rename it as required. You can edit the LDF file in a text editor such as NotePad.
The format of lines in an LDF file is:
identifier: string
The strings to translate are arranged into sections according to the windows they appear on. For example, the section which contains the text for the "About" window is contained in the about section, and this begins at the line:
section: about
There is also a general section at the beginning of the LDF file for frequently-used strings, which appear on multiple windows, such as "OK" and "Cancel".
The strings then appear on subsequent lines - the first line is:
title: About
which means the title of the window is "About". Here, "title" is the identifier and should not be changed - the string to the right of the colon, "About", is the string that needs translating.
Don't translate section lines or comment lines which begin with a # character.
If you've created an LDF file for a previous version of Quest, look for the comment lines in the current ENGLISH.LDF to see which strings have been added or updated.
Many lines have ampersand "&" characters in them - these correspond to which letter is underlined when the user presses the Alt key. For example, usually when you see a File menu in a program, the "F" is underlined, so the user can access the menu by pressing Alt and F - so this is expressed as "&File". Obviously any translated version might not have the same letter in it, so the "&" needs to be moved, but on any window the underlined letter should be unique. You can tell if you've not got a unique letter when you test your LDF file in Quest - you should be able to use the Alt+Letter combination to get to everything. If you need to press the Alt+Letter combination twice, you've used the same letter twice, which means one of them needs changing.
The text: help section near the end of the file is a special case. What follows this is the text for Quest's "Quick Help Guide" which appears when the player clicks the Help link in the program. Everything between the "text: help" and the "<" is part of the help file and needs to be translated. This help text uses text formatting codes which should be left unchanged.
One complication with the help text is it describes commands the player types in. Somebody playing a Spanish game will usually be typing in Spanish commands - but the current version of Quest has no way of specifying the standard game commands. This will be addressed in a future version of Quest, which will have an updated LDF specification.