Microsoft Office may be the most popular productivity suite on the market, but it isn't your only option. OpenOffice is a free open-source alternative with similar applications to Microsoft Office, plus a few additional utilities.

There are no restrictions on OpenOffice's use, even for businesses. And getting to grips with the new software shouldn't be an issue - its interface is extremely similar to that of its Microsoft rival.

Core applications include: Writer, a word processor; Calc, a spreadsheet tool; Impress, a presentations program; Base, a database utility; and Draw, a vector package that can also handle basic 3D graphics.

OpenOffice is compatible with Office, particularly so up to Office 2003. Microsoft's substantial rewrite for the 2007 suite could cause some problems, although the same is true for users of earlier releases of Office itself.

Over the following pages, we look at ways in which you can improve OpenOffice compatibility with Microsoft documents. With a few tweaks, it's possible to seamlessly exchange Writer, Calc and Impress files with colleagues who use Microsoft Office.

We also concentrate on the advanced features within Calc. By using this app to create a comparison between the present value of leasing a car and buying it outright, you'll see it's no poor cousin to Excel.

And this is the real value of OpenOffice. Some 20 years of design means it's become an extremely sophisticated but also immensely usable collection of productivity tools.

Just because the suite is free, that doesn't mean it's inferior to Microsoft Office. If you're looking to upgrade your own applications, the open-source route could be the best way to go in these cash-strapped times.

Over the following pages, we'll help you improve OpenOffice's compatibility with other productivity suites and teach you how to perform complex calculations in Calc.

Improve OpenOffice's compatibility

1. Download and install OpenOffice 3.0. The suite works seamlessly with versions of Microsoft Office up to and including the 2003 release. It's also possible to use the software with Office 2007, but you may wish to tweak some settings first. Go to Tools, Options, Writer.

OpenOffice compatibility: Step 1

2. In the dialog box that pops up, click the plus sign next to Writer and select Compatibility. This dialog also provides options for compatibility with earlier versions of OpenOffice. Some settings, such as leading and word wrap, can provide unexpected results when working with Office files. These settings can be modified here.

OpenOffice compatibility: Step 2

3. There's also an option to convert your Microsoft Office files into the native OpenOffice format using the conversion wizard. Launch any OpenOffice program and go to File, Wizards, Document Converter. Select the document type you wish to convert (such as Word, PowerPoint or Excel) and click Next.

OpenOffice compatibility: Step 3

4. One incompatibility between this program and Microsoft's lies with Excel macros - Office uses Visual Basic for Applications (VBA) to program macros, OpenOffice a different type of Basic. But, while you can't work with them, you can still preserve Excel macros under Tools, Options, Load/Save, VBA Properties.

OpenOffice compatibility: Step 4

5. If you need to share documents with colleagues who work only with Microsoft Office, elect to save in that file format by default. Go to Tools, Options, Load/Save, General and make sure that you select the appropriate Microsoft format under the heading ‘Default file format'.

OpenOffice compatibility: Step 5

6. OpenOffice will open Microsoft Office documents up to version 2003 with ease, but it's possible to export your documents in other formats for wider compatibility. Select File, Export and then choose the file format. Here you'll be given options to save to formats such as PDF and wiki text.

OpenOffice compatibility: Step 6

>> NEXT PAGE: Get to grips with OpenOffice Calc

Get to grips with OpenOffice Calc

1. In common with Excel, Calc uses formulae to perform complex calculations. Here, we'll use it to work out the present value of spreading lease payments against purchasing a car outright, entering basic information regarding costs, interest rates and so on.

OpenOffice Calc: Step 1

2. When comparing interest rates, the typical comparison is made using what's known as the ‘effective' interest rate - this is generally slightly higher than the annual percentage rate (APR). Click the Function wizard button in the toolbar above the worksheet and select Effective from the list of financial functions.

OpenOffice Calc: Step 2

3. In the dialog box that appears, select the cell where you recorded the stated APR. Next, enter the number of payments for the year (usually 12) and click ok. The spreadsheet will calculate the effective interest rate and return a value for the cell where you entered the formula.

OpenOffice Calc: Step 3

4. The next step is to create the section of our spreadsheet that will compare results. Before working out the calculations, we need some basic formatting in the spreadsheet in order to display our results visually. For the Payment column, point to the cell where you entered the list price of the car.

OpenOffice Calc: Step 4

5. Leasing is more complex, because we wish to calculate the ‘present' value for our monthly payments. Click the formula button on the toolbar and select the cell for monthly payments, followed by financial function PV. Click next and, under Rate, select the cell containing the APR divided by 12.

OpenOffice Calc: Step 5

6. Two other fields are required to work out the present value. First, we must select the cell containing the payment period, as well as the amount paid each month in the field headed PMT. When these values are entered into the formula, you're ready for the final part of the equation.

OpenOffice Calc: Step 6

7. For the final total in the Lease column, we also need to enter the present value for the final payment. Click the function button, add a plus sign after the previous value and enter the formula CellX1/(1+CellX2/12)^CellX3, where CellX1 is the final payment value, CellX2 is the APR and CellX3 is the payment period.

OpenOffice Calc: Step 7

8. With some formatting applied via the Autoformatting feature in Calc, we can create a decent-looking table that contains the formulae for working out the values of leasing versus immediate payment. By changing the values in the cells at the top of the spreadsheet, this will return different totals below.

OpenOffice Calc: Step 8