GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
Spreadsheet::WriteExcel is a Perl module which can be used to create native Excel binary files. Formatted text and numbers can be written to multiple worksheets in a workbook. Formulas and functions are also supported. It is 100% Perl and doesn't require any Windows libraries or a copy of Excel. It will also work on the majority of Unix and Macintosh platforms. Generated files are compatible with Excel 97, 2000, 2002, and 2003, and with OpenOffice and Gnumeric. An older version also supports Excel 5/95.
Calligra is an integrated suite of applications that cover office, creative, and management needs. It offers applications on both desktop computers and mobile platforms like tablets and smartphones. OpenDocument Format (ODF) is used, making it compatible with OpenOffice.org, LibreOffice, and Microsoft Office. Calligra Suite contains the following applications: Calligra Words (word processor), Sheets (spreadsheets), Stage (presentations), Flow (diagrams and flowcharts), Kexi (visual database creator), Braindump (note taking), Plan (project management), Krita (drawing), and Karbon (vector graphics).
KOffice is an integrated office suite based on the KDE libraries. KOffice currently includes KWord, KSpread, KPresenter, KChart, Karbon14, Krita, Kexi, KFormula, Kugar, and Kivio. There are no special mail and news clients included in KOffice, because there are KMail and KNode available for KDE anyway. All KOffice components work together, and you can embed every KOffice component into any other KOffice component. This is realized using the KParts object model.