Starting with TeX Live 2010, the various formats, that directly generate PDF, default to generating PDF 1.5. This is generally a good thing, but it can lead to compatibility issues with some older PDF viewers. This package changes the version of PDF generated with formats (based on pdfTeX or LuaTeX in PDF mode), back to 1.4 for documents that need to achieve maximal compatibility with old viewers.

The author is Manuel Pégourié-Gonnard.