Authors of GNU Automake.

David Mackenzie
  First version of most ".am" files.
  Wrote sh version of automake.in.

Tom Tromey
  Touched all ".am" files.
  Rewrote automake.in

Alexandre Oliva
  Some of the user-side dependency tracking system.
  Some more random hacking.

Alexandre Duret-Lutz
  Major overhaul of everything.
  Maintenance since 2002.

Ralf Wildenhues
  Random breakage.
  Maintenance since 2006.

Stefano Lattarini
  Testsuite overhaul.
  TAP support and custom testsuite drivers.
  Random breakage.
  De-facto maintenance since 2012.