Michael Tiemann is vice president of open source affairs at Red Hat, Inc., and former President of the Open Source Initiative. He was the chief technical officer of Red Hat. He served on a number of boards, including the Embedded Linux Consortium, the GNOME Foundation advisory board, and the board of directors of ActiveState Tool Corp. He is also co-owner with Amy Tiemann of Manifold Recording Studios.
He co-founded Cygnus Solutions in 1989. His programming contributions to free software include authorship of the GNU C++ compiler and work on the GNU C compiler and the GNU Debugger. Tiemann is featured in the 2001 documentary Revolution OS. Opensource.com profiled him in 2014, calling him one of "open source's great explainers."
He earned a bachelor's degree from the Moore School of Electrical Engineering in 1986 at the University of Pennsylvania.