gEdit - Lightweight but powerful text editor of the GNOME project. - http://www.gnome.org/projects/gedit/
Dia - A diagram creation tool that supports UML modeling and runs primarily on Linux but also Windows and Irix. The interface is similar to the commercial Microsoft Visio. [Open Source, GPL] - http://www.gnome.org/projects/dia/
GnuCash - An application aimed at personal finances and home users. - http://www.gnucash.org/
Gnumeric - A spreadsheet. It is part of the GNOME desktop environment. - http://www.gnome.org/projects/gnumeric/
rCalc - A fast and light symbolic calculator for the GNOME desktop environment. It aims to occupy the middle ground between simple point-and-click calculators and full featured mathematical packages. - http://rcalc.sourceforge.net/
Gnome Office - Meta-project to coordinate productivity applications for Gnome Desktop: AbiWord word processor, Gnumeric spreadsheet, and Gnome-DB data access components. - http://www.gnome.org/gnome-office/