Miller ported the Linux kernel to the Sun Microsystems SPARC in 1996 with Miguel de Icaza. He has also ported Linux to the 64-bit UltraSPARC machines, including UltraSPARC T1 in early 2006 and later the T2 and T2+. As of 2010 he continues to maintain the sparc port (both 32-bit and 64-bit).
He worked at the Rutgers University Center for Advanced Information Processing, at Cobalt Microserver, and then Red Hat since 1999.
In April 2008, Miller contributed the SPARC port of gold, a from-scratch rewrite of the GNU linker.
He gave a talk on "Multiqueue Networking Developments in the Linux Kernel" at the July 2009 meeting of the New York Linux Users Group.
David delivered the keynote at netdev 0.1 on February 16, 2015 in Ottawa. He also delivered the keynote at Ottawa Linux Symposium in 2000, and another keynote at Linux.conf.au in Dunedin in January 2006.
As of April 2017, Miller is #1 in "non-author signoffs" patches, modifications to the linux kernel reviewed by the subsystem maintainer that ultimately applies them.
