Michael Tiemann is an open source software pioneer.  He created GNU C++, first native-code C++ compiler, in 1987.  He also made numerous contributions to the GNU C compiler (GCC), debugger (GDB), and other GNU software.  In 1989 he co-founded Cygnus Solutions, the first company to provide commercial support for open source software.  In January 2000, Cygnus Solutions was acquired by Red Hat, and Tiemann became Red Hat's CTO.  In 2004, he became the company's vice president of open source affairs.  He served as President of the Open Source Initiative from 2005-2012.  He has been the Project Lead for OS-Climate since 2019.