Marc has been using linux since 0.99pl15f (slackware 1.1.2, 1994), both as a sysadmin and userland contributor.
He has worked for various tech companies in the Silicon Valley, including Network Appliance, SGI, VA Linux, Sourceforge.net, and now Google both a server sysadmin and software engineer.
He has done hacking in various areas like mail with exim, mailman, SpamAssassin, as well as maintained various distributions