LaTeX2e's filecontents and filecontents* environments enable a LaTeX source file to generate external files as it runs through LaTeX. However, there are two limitations of these environments: they refuse to overwrite existing files, and they can only be used in the preamble of a document. The filecontents package removes these limitations, letting you overwrite existing files and letting you use filecontents/filecontents* anywhere.

The author is Scott Pakin. The package is Copyright © 2009 Scott Pakin.