The free spreadsheets software available to us nowadays are quite feature rich and are perfectly suitable for most businesses. If you do not have a large number of existing spreadsheets that use macros or application specific functionality, you can easily switch to one of the free choices.
Transferring large numbers of existing spreadsheets from one application format to another can be a little more difficult, as most complex spreadsheets use macros or mathematical formulae provided by their current application. To change the application you will want the new one to support the features you use and ideally provide a method of automatically translating the macros and functions for you.
It can open Excel files, though the formatting may look somewhat different especially with embedded charts, and there is no VBA support by default. The lack of VBA support will be a problem for people that have large amounts of Excel file. OpenOffice 3 Calc will have a limited support for VBA out of the box.
KSpread (KOffice) has most of the features available in the other two tested here, but it didn’t seem to have data filtering. This a frequently used feature that most users carrying out the simplest of data analysis would expect. It is also very slow in loading files. A 500 row, 20 column spreadsheet took over 10 times longer to open in KSpread than it did in Calc. But it can open excel files albeit very slowly and without VBA support.
Gnumeric is also adequate for general spreadsheet tasks. Like the other two it can open excel files, and again without VBA support. There is also quite a bit of discrepancy from the original formatting in Excel. It has a large function library and supports the common features such as data sorting and filtering, but lacks pivot tables support. It is quick to open files, but does not have full support for OpenDocument Spreadsheet format.
As already mentioned the choice of spreadsheets can be difficult if you need to convert a lot of existing files with macros. This situation, however, is improving though with future versions (i.e. OpenOffice 3.0) promising a VBA import feature.
Like word processors, there shouldn’t be much in technical terms holding the average presentation package user from switching to a different package. The biggest potential issue seems like transitions support (i.e. the animation that is show when going from one slide to another), where one application may not support some of the transitions available another.
Impress (OpenOffice.org), not only has pretty much all of the PowerPoint features, but also the ability to save files in HTML, PDF and SWF formats allowing easy publishing to the Web. It has presentation wizard to start you off, as well as templates and transitions. It can import and export PowerPoint files with minimal quirks. It supports 2D and 3D text creation using FontWork.
KPresenter (KOffice) is sufficient for creating screen, or printed presentations. It has the basic features such as layout control and font formatting, but it lacks more advanced font styling. It has a HTML slideshow export feature for publishing to the web, but lacks the PDF and SWF features which would be more useful for users who want to download and keep presentations.
Desktop databases are generally popular only in very small businesses. Larger businesses tend to have some sort of database infrastructure in place for their various database applications. If you believe that you may need to handle large amounts of data or may need to allow more than one person to access the database application at the same time, you really should pursue a proper database management system based solution.
Desktop databases can still be handy for quick and small databases which are portable and give you access to some data while you are disconnected from your office network.
Base (OpenOffice.org) allows you to create either a standalone database or connect to MySQL/PostgreSQL. It lets you create forms and reports and supports customised functionality using macro. It has Table Wizards, Relation Designer and Forms Wizard to help you easily create your whole database application with step by step instructions. The wizards can help you create a form for a table or query with sub-forms for the related tables.
Kexi (KOffice) touts itself as “Microsoft Access for Linux”. Similar to OpenOffice Base, it has visual designers for tables, queries and forms, but it does not have wizards that let you quickly create a full forms in a few steps. Kexi supports scripting using Python and Ruby. Again like Base, it can be used as a front end to external Database management systems such as MySQL.
Glom is strictly a database forms interface. It provides a friendly frontend to the database, but unlike the other two it does not provide a standalone database.
It does let you create databases using PostgreSQL for storing your data, but these are not as portable as the single file database/forms combinations offered by Base and Kexi. Making it less suitable for people after a simple desktop database application.