OpenMPT is an open source audio module tracker for Windows. It was named by Computer Music as one of the top five free music trackers. It originally started out under the name ModPlug Tracker, and was developed by Olivier Lapicque.

Originally called ModPlug Tracker, it was initially developed as a plug-in named Modplugin for Internet browsers, to allow users to listen to music modules (for example, IT, XM, S3M, and MOD) present in some websites. ModPlug Tracker, along with a player application named ModPlug Player later evolved from this plug-in.

OpenMPT's main distinguishing feature is its native Windows user interface. Most trackers, even newer ones such as Renoise, have interfaces modelled after the older DOS trackers such as FastTracker II. Although many old-school musicians who use trackers prefer this kind of old fashioned GUI, newcomers have been attracted to OpenMPT's alternative interface.

OpenMPT makes use of features common to Microsoft Windows programs, such as context menus for effect selection, "tree" views for files, samples, and patterns, and drag-and-drop functionality throughout. It supports both loading and saving of IT (Impulse Tracker), XM (FastTracker Extended Module), MOD, S3M (Scream Tracker 3) and MPTM (its own file format) files, loads many sample file formats, and has some support for DLS banks and soundfonts.

In December 1999, Olivier Lapicque sent the module-playing parts of ModPlug Trackers's source code to Kenton Varda, under the GPL, to write a plugin for XMMS based on the code. The source code was later released to the public domain, and the mod-playing code was split off into a separate library, libmodplug, maintained as part of the ModPlug XMMS Plugin project. This project lay dormant from late 2003 until early 2006, when it was picked up again. As of December 2009, the last official project release dates to June 2009. Beta versions are released from time to time. Today, libmodplug is included in many Linux distributions as a default audio plugin for playing module files.