Archiever:
1. 7-Zip - compression program

http://www.7-zip.org

2. IZArc - compression program

http://www.izarc.org

3. TugZIP - compression program

http://www.tugzip.com

4. CabPack - compression program

http://www.larshederer.homepage.t-online.de/english.htm

5. Universal Extractor - extract files from any type of archive

http://legroom.net/software/uniextract

6. Peazip - compression program

http://www.peazip.org/

7. KGB Archiver

http://sourceforge.net/projects/kgbarchiver/

8. ZipGenius

http://www.zipgenius.com/

PDF:
1. Adobe Reader - pdf reader

http://www.adobe.com/products/acrobat/readstep2.html

2. Foxit PDF Reader

http://www.foxitsoftware.com/

3. PDF X-Change PDF Viewer

http://www.docu-track.com/home/prod_user/PDF-XChange_Tools/pdfx_viewer

4. PDFCreator - create pdf documents

http://sector7g.wurzel6.de/pdfcreator/index_en.htm

5. BullZip PDF Printer - create pdf documents

http://www.bullzip.com/

6. Free PDF to Word Converter - converts pdf documents back to Word .doc

http://www.hellopdf.com/