Evince is a document viewer for multiple document formats. It currently supports pdf, postscript, djvu, tiff and dvi. (GPL)
Linux - FreeBSD
PDFedit is a free (and open source) editor for manipulating PDF documents. GUI version + commandline interface. (GPL)
Linux - FreeBSD
PDFsam basic is a free and open source, platform independent software designed to split, merge and rotate pdf files. (GPL)
Cross-platform
4 applications