We describe OPENMATREX, a free/open-source example-based machine translation (EBMT) system based on the marker hypothesis, comprising a marker-driven chunker, a collection of chunk aligners, and two engines: one based on a simple proof-of-concept monotone EBMT recombinator and a Moses-based statistical decoder. OPEN-MATREX is a free/open-source release of the basic components of MATREX, the Dublin City University machine translation system.