.Most popular Document file extensions:
.wps - Microsoft Works document
.pub - Microsoft Publisher document
.xls - Microsoft Office Excel spreadsheet
.odt - OpenOffice.org Writer text document
.docx - Microsoft Word 2007 XML based document file format
.pps - Microsoft PowerPoint slideshow
.pages - iWork Pages document file
.ods - OpenOffice.org Calc Spreadsheet file
file extension BTX - BibTeX document
File extension BTX description:
TeX is a typesetting language. Instead of visually formatting your text, you enter your manuscript text intertwined with TeX commands in a plain text file. You then run TeX to produce formatted output, such as a PDF file. Thus, in contrast to standard word processors, your document is a separate file that does not pretend to be a representation of the final typeset output, and so can be easily edited and manipulated.