Free popular software for linux

POI provides a java ports of popular OLE 2 file formats.
The POI project contains several components for dealing with popular OLE 2 formats in Java. POIFS is a pure Java implementation of the OLE 2 Compound document format.
HSSF is a pure Java implementation of Excel 97 XLS file format based on POIFS. HSSF Serializer is a pure Java serializer for Cocoon 2 that uses the Gnumeric XML format to output XLS.
Full documentation of the POIFS file format is included. If you wish to output reports in the Excel file format, or if you have existing XML documents that you need to get into Excel, then this project is probably what youre looking for.
Enhancements:
- Support for evaluating formulas in HSSF, initial support for HSLF (PowerPoint), and support for editing document properties (HPSF).

GNOME FCE Ultra (also known as gfceu) is an interface for the popular Nintendo Emulator, FCE Ultra. GNOME FCE Ultra is designed for the GNOME desktop, and allows the user to easily play NES ROM images.
Main features:
- Network play
- Custom input configuration
- Fullscreen support
- Full sound support
- High compatibility and accurate emulation

jGGTrans is a gateway between Jabber/XMPP and Gadu-Gadu (which is a very popular proprietary instant messaging protocol in Poland).

GG Transport allows Jabber users to use their favorite XMPP client to talk with their GG-using friends.

Console Jabber Client is a Jabber client with text-based user interface resembling those known from popular IRC clients.

CJC is a Jabber/XMPP client for text terminals. Console Jabber Client uses pyxmpp library for XMPP comunication and curses for screen output. It is not finished yet, but still quite usable. Its user interface is resembling those of popular IRC clients like irssi or BitchX.

TuxMathScrabble is a math-version of the popular board game for children aged 4-10. The game features drag-and-drop tiles for the user, while Tux moves his own.

The game challenges young people to construct compound equations and consider multiple abstract possibilities.

Dancing penguins come out of the tiles when your move is correct (like a cuckoo-clock). Tux is animated as well.

NOCOL is a popular system and network monitoring (network management) software that runs on Unix systems and can monitor network and system devices.
The software uses a very simple architecture and is very flexible for adding new network management modules.
Enhancements:
- Unix syslog file monitor (match any specified regular expression)
- NTP (Network Time Protocol) stratum monitor
- mailmon merged in with hostmon-client
- nsmon can monitor multiple domains
- apcmon for monitoring APC Smart UPSs
- ciscomon for monitoring Cisco router specific parameters
- Web interface for displaying events (www/webnocol)
- use of latest CMU SNMP library
- Tcl/Tk interface

xMule is an easy to use multi-platform synchronizing fork of the popular eMule client.
Based upon the wxWindows library and GNU C++, xMule aims to support the Linux, and *BSD operating systems.