OPENOFFICE.ORG: The Free and Open Productivity Suite

Great software
OpenOffice.org 3 is the result of over twenty years' software engineering. Designed from the start as a single piece of software, it has a consistency other products cannot match. A completely open development process means that anyone can report bugs, request new features, or enhance the software. The result: OpenOffice.org 3 does everything you want your office software to do, the way you want it to.

Easy to use
OpenOffice.org 3 is easy to learn, and if you're already using another office software package, you'll take to OpenOffice.org 3 straight away. Our world-wide native-language community means that OpenOffice.org 3 is probably available and supported in your own language. And if you already have files from another office package - OpenOffice.org 3 will probably read them with no difficulty.

and it's free
Best of all, OpenOffice.org 3 can be downloaded and used entirely free of any licence fees. OpenOffice.org 3 is released under the LGPL licence. This means you may use it for any purpose - domestic, commercial, educational, public administration. You may install it on as many computers as you like. You may make copies and give them away to family, friends, students, employees - anyone you like.

Now you can download from here! for intel flatform

7-Zip is a file archiver with a high compression ratio

high compression ratio in new 7z format with LZMA compression
Supported formats:
o Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
o Unpacking only: ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z.
For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
Strong AES-256 encryption in 7z and ZIP formats
Self-extracting capability for 7z format
Integration with Windows Shell
Powerful File Manager
Powerful command line version
Plugin for FAR Manager
Localizations for 74 languages
Download 7-Zip 4.65 (2009-02-03) for Windows here for 32bit or for x64 from here

AVIRA ANTIVIR PERSONAL

Avira AntiVir Personal is freeware. The application is for personal use only. Like most antivirus software, it scans disks for viruses and also runs as a background process, checking each opened and closed file. It can detect and possibly remove rootkits.[1] It also performs Internet updates (daily by default) in which it opens a window, with an advertisement suggesting the user to purchase Avira AntiVir Premium. Avira updated all their products to version 8.0 on 14 April 2008. Version 8.0 free has a faster scanning engine and a more refined user-interface. for freeware edition now you can download from here or go to avira website

DOWNLOAD FIREFOX 3

Firefox is available in over 45 languages, thanks to the contributions from Mozilla community members around the world.
English Version for windows platform , Mac Os X and for Linux