Kurt Sibold, chairman of the board of the software giant's German subsidiary, accused the initiators of a pro-Linux online petition of smearing the reputation of his company.
In an open letter to the signatories of the petition, Sibold wrote: "What you are achieving by supporting this campaign is public discrimination, accusing our products and services of being undemocratic and an obstacle to democracy".
The petition campaign was launched last week with 12 initial signatories, among them several members of parliament and open-source fans, including Red Hat's managing director for central and eastern Europe, Dieter Hoffmann. Within two days, more than 11,000 other supporters had added their names.
The petition asks the Bundestag to take a stand against "monopoly positions," pointing out that Microsoft's operating system, Web browser, and e-mail programs hold a market share of over 90% in Germany. It also appeals to government bodies to implement open-source software for "democratic" reasons.
This proved too much for Sibold, who wrote: "Open source software is ... not per se a guarantee for free-market competition, just as a decision to use my company's products is not at present, nor was it in the past, an 'undemocratic' decision."
A parliamentary committee is due to decide by the end of this month whether to renew Microsoft licences for the Bundestag's some 5,000 PCs, or to switch to Linux.