As the title says: what system would you use to create mathematical documents with a level of papers/books? Which one is more complete? Which one is more friendly, clear, easy-to-use, etc.?
Do you have to have some special program to use either? Do you have to have some special program to create documents or can I create documents with regular PDF viewer and/or with Ghostscript or GSview (or anything else)? Or would I need to purchase some special addition to this free-downloadable programs in order to actually write (and eventually print) documents?
Many thanks for any input.