I am not sure if this question is suitable for superuser instead, but I'll ask anyway.
Currently I'm writing on my documentation for my final project. I must append several other LaTeX documents as enclosure. They must be mentioned in the first Table of Contents as alphabetical appendix. I tried the package subfiles, but the subsequent TOC´s are always empty exept in case of translating them alone.
Is there any other way to append multiple full documents with there own documentclass??
subfiles is a very simple package - it doesn't try to do anything other than manage the document-level macros. You will need to issue an \appendix cs before each inclusion of a subfile.
Beware of the different latex documents sharing auxiliary files: if they do this, then subfiles will basically not work - you will be better off using the pdfpages package that absz mentions.
Postscript If you want the subsidiary documents to have their own tables of contents, you have either to change their auxiliary files (at least, their .aux and .toc files), or switch to another mechanism. Maybe minitoc will fit better?
Couldn't you strip out the preamble of the other LaTeX documents and then use \include or \input depending on whether you want pagebreaks?