Microsoft's recent $135 million purchase of Canadian Corel contains details, revealed in Corel's filing with the U.S. Securities and Exchange Commission, that prove that Microsoft is keeping its Linux options open. For some time, the Redmond company has been torn concerning the open-source OS. The applications wing of the company fears missing an opportunity to sell its business software to Linux users, especially if the .NET venture becomes a significant portion of revenue. On the other hand, the Windows OS portion of the company fears doing anything that would give credibility to Linux. As Microsoft's agreement with Corel, giving it the right to have Corel port .NET code to Linux, is now a matter of public record, Microsoft is only downplaying the arrangement. There is some speculation that the company's apparent relationship with another operating system may prove useful in future antitrust negotiations.