What is the RTM file format?
The .rtm extension identifies a Real Tracker Music Module, a binary tracker music file produced by Real Tracker - a DOS-era demoscene music sequencer developed by Arnaud Hasenfratz in the mid-to-late 1990s. Like the .mod, .xm, .s3m, and .it formats it resembles, an .rtm file is a self-contained package: it bundles both the digital instrument samples and all sequencing data into a single binary file, so the song sounds identical on any compatible player without external soundbanks.
An .rtm file opens with an ASCII identifier string at byte offset 0, naming the tracker and module format version. The rest of the file follows a structured layout:
- Song order table listing the sequence in which patterns play back
- Pattern data - cells of note, instrument, and effect values spread across up to 32 channels
- Instrument definitions, each referencing one or more sample entries
- Embedded raw PCM sample data (8-bit or 16-bit, uncompressed)
The format is little-endian binary with no compression and no encryption. File sizes typically run from 50 KB to roughly 4 MB, dominated by the embedded samples. Playback rate for each instrument sample is stored per-sample (commonly 8 Hz - 44.1 kHz); the final mix rate is determined by the player. Real Tracker is no longer in active development, and .rtm files survive mainly in demoscene and module archives. Modern players such as OpenMPT, XMPlay, and VLC can open them on Windows; on Linux, libxmp and Audacious provide compatible playback.
Security & safety
RISK: LOWA Real Tracker module is passive sample+sequence data with no scripting, so opening one in a module player is safe. The only practical caution is the usual one: download players from the official sites (OpenMPT, VideoLAN, un4seen) rather than 'codec pack' or fake 'RTM player' bundles that can carry adware. (If your file is actually a LabVIEW Run-Time Menu .rtm, it's a LabVIEW project resource - open it only within a trusted LabVIEW project.)
Format details
in a nutshell- LabVIEW Run-Time Menu (National Instruments) - An .rtm holding a customized menu definition referenced by a LabVIEW VI, created with LabVIEW's Menu Editor - a programming resource file, not audio.
- dRofus / ReBirth-related data - A few other applications (e.g. the dRofus database tool, and ReBirth-era song data in some references) have used .rtm for their own unrelated files.
Programs that open RTM files
Windows3 apps
VLC media player
Open-source Drag the .rtm into VLC to play it; VLC includes a module-music (libmodplug) decoder. 
OpenMPT (Open ModPlug Tracker)
Open-source Open the .rtm to play it and inspect/edit patterns, instruments and samples - the standard free modern tracker. 
macOS2 apps
OpenMPT (via Wine) / Schism Tracker
Open-source Schism Tracker (cross-platform) plays/edits many module formats; or run OpenMPT through Wine/CrossOver. 
Linux2 apps
libxmp / xmp (CLI) and Audacious
Open-source Play from the terminal: 'xmp song.rtm', or open in the Audacious player which uses libxmp. Technical details
deep spec| Format type | Sample-based tracker music module (binary) |
| Developer | Arnaud Hasenfratz (Real Tracker) |
| Platform origin | MS-DOS; demoscene community, mid-to-late 1990s |
| File encoding | Binary, little-endian |
| Header signature | ASCII identifier string at byte offset 0 naming the tracker and module format version |
| Channel count | Up to 32 simultaneous channels (comparable to the XM family) |
| Sample bit depth | 8-bit or 16-bit raw PCM per instrument sample |
| Sample playback rate | Per-instrument: commonly 8 Hz - 44.1 kHz; final mix rate is set by the player |
| Compression | None; sample data is stored as uncompressed PCM (sometimes delta-encoded) |
| Typical file size | 50 KB - 4 MB, dominated by embedded PCM sample data |
| Internal structure | Header → song order list → pattern data (note/instrument/effect cells) → instrument definitions → embedded sample data |
| MIME type | audio/x-rtm (also served as application/octet-stream) |
| Related formats | .mod, .xm, .s3m, .it - all MOD-family tracker modules sharing the same self-contained playback model |
| Current status | Discontinued; Real Tracker is no longer developed; .rtm files survive in demoscene and module archives |
| Released | Mid-to-late 1990s (Real Tracker, DOS-era demoscene tracker) |
| Latest version | Real Tracker 2.x module format; the program is no longer developed |
| Specification | wiki.multimedia.cx |
RTM conversions
Community Q&A
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