Michael Dell, billionaire chairman of Dell Inc., has given Red Hat a $99.5M injection.

NEW YORK (CNN/Money) - Red Hat is getting a $99.5 million boost from Michael S. Dell, billionaire founder and chairman of Dell Inc., according a regulatory filing.

Through his private investment firm, MSD, Dell bought the largest share of $600 million in debentures offered by the software developer in January 2004, a Securities Exchange Commission filing showed.

Red Hat's main product, the Linux operating system for PCs, is a direct competitor to Microsoft's Windows. The Raleigh, N.C.-based company also provides support services for "open source" technology, which is software developed by communities of programmers for free use.

Dell (Research) is the nation's largest PC maker.

Debentures are similar to bonds in that the issuer promises a fixed return for a stated period of time on the investment.

In the case of a public company, a debenture can also be converted into shares or equity.