Question: What do you have when you mate a spreadsheet with a wiki?

Answer: A browser-based open source spreadsheet called wikiCalc.

Released a few days ago in Beta by Dan Bricklin, the father of the spreadsheet, wikiCalc is already in use by individuals and businesses.

"Most people who are using it, don't tell me," said Bricklin, who is president of software develop Software Garden, in an interview Thursday. He said a government agency " he declined to release its name " and some businesses are testing wikiCalc. Bricklin developed the pioneering VisiCalc spreadsheet.

"It's called WikiCalc " and it's appropriately named," he said. "It's a spreadsheet first. Then it's a wiki. You take the data out, make changes, edit it, and put it back. You always use a browser."

The collaborative software enables different users to access the solution via passwords with applications able to run on servers, individual PCs, or on Internet-hosted sites. Bricklin said he constructed wikiCalc with the idea that it would serve 10 authors for each page, but that a million readers could access it. Users can publish the results as Web pages. It operates on Windows, Unix and Mac software.

In describing wikiCalc's features, Bricklin noted the features it doesn't have: he explained that wikiCalc is not for heavy calculation or for large data spreadsheeting. "It is not a data processing system like Excell and other high-end spreadsheets," he said. "It is not a database management system."

WikiCalc will be deployed commercially by SocialText, which Bricklin notes markets wiki-based and open source products. He added that SocialText offers products written in Perl, the same software discipline he used to write wikiCalc. Bricklin wrote the initial version of wikiCalc in the last year and is offering it under a GPL open source license. He added that the Beta version still needs to be debugged, needs more testing, and will be developed further in the coming months.

Bricklin said Google's recent unveiling of its Web-based spreadsheet helps generate interest in the Software Garden product, but he noted that Google's spreadsheet isn't a wiki.

One wikiCalc advantage will be its capability of residing on corporate servers and at the same time of being downloaded to a laptop for individual use.